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Foster L B Co – ‘10-Q’ for 3/31/18 – ‘XML’

On:  Wednesday, 5/2/18, at 3:15pm ET   ·   For:  3/31/18   ·   Accession #:  352825-18-15   ·   File #:  0-10436

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  As Of               Filer                 Filing    For·On·As Docs:Size

 5/02/18  Foster L B Co                     10-Q        3/31/18   89:6.5M

Quarterly Report   —   Form 10-Q   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML    487K 
 2: EX-10.3     Material Contract                                   HTML     69K 
 3: EX-10.4     Material Contract                                   HTML     50K 
 4: EX-10.5     Material Contract                                   HTML     72K 
 5: EX-10.6     Material Contract                                   HTML     26K 
 6: EX-10.7     Material Contract                                   HTML     58K 
 7: EX-10.8     Material Contract                                   HTML    145K 
 8: EX-31.1     Certification -- §302 - SOA'02                      HTML     32K 
 9: EX-31.2     Certification -- §302 - SOA'02                      HTML     32K 
10: EX-32.0     Certification -- §906 - SOA'02                      HTML     29K 
17: R1          Document and Entity Information                     HTML     44K 
18: R2          Condensed Consolidated Balance Sheets               HTML    109K 
19: R3          Condensed Consolidated Balance Sheets               HTML     35K 
                (Parenthetical)                                                  
20: R4          Condensed Consolidated Statements of Operations     HTML     78K 
21: R5          Condensed Consolidated Statements of Comprehensive  HTML     45K 
                Loss                                                             
22: R6          Condensed Consolidated Statements of Comprehensive  HTML     29K 
                Loss (Parenthetical)                                             
23: R7          Condensed Consolidated Statements of Cash Flows     HTML    110K 
24: R8          Financial Statements                                HTML     41K 
25: R9          Business Segments                                   HTML     74K 
26: R10         Revenue                                             HTML     92K 
27: R11         Goodwill and Other Intangible Assets                HTML    103K 
28: R12         Accounts Receivable                                 HTML     31K 
29: R13         Inventories                                         HTML     40K 
30: R14         Property, Plant and Equipment                       HTML     43K 
31: R15         Investments                                         HTML     47K 
32: R16         Long-Term Debt                                      HTML     53K 
33: R17         Fair Value Measurements                             HTML     60K 
34: R18         Earnings Per Common Share                           HTML     49K 
35: R19         Stock-Based Compensation                            HTML     53K 
36: R20         Retirement Plans                                    HTML     62K 
37: R21         Commitments and Contingent Liabilities              HTML     69K 
38: R22         Income Taxes                                        HTML     33K 
39: R23         Subsequent Events                                   HTML     26K 
40: R24         Financial Statements (Policies)                     HTML     53K 
41: R25         Business Segments (Tables)                          HTML     76K 
42: R26         Revenue (Tables)                                    HTML     73K 
43: R27         Goodwill and Other Intangible Assets (Tables)       HTML    105K 
44: R28         Inventories (Tables)                                HTML     41K 
45: R29         Property, Plant and Equipment (Tables)              HTML     41K 
46: R30         Investments (Tables)                                HTML     45K 
47: R31         Long-Term (Tables)                                  HTML     39K 
48: R32         Fair Value Measurements (Tables)                    HTML     53K 
49: R33         Earnings Per Common Share (Tables)                  HTML     48K 
50: R34         Stock-Based Compensation (Tables)                   HTML     46K 
51: R35         Retirement Plans (Tables)                           HTML     64K 
52: R36         Commitments and Contingent Liabilities (Tables)     HTML     38K 
53: R37         Financial Statements (Narratives) (Details)         HTML     28K 
54: R38         Business Segments (Reconciliation of Revenue from   HTML     37K 
                Segments to Consolidated) (Details)                              
55: R39         Business Segments (Reconciliation of Operating      HTML     52K 
                Profit (Loss) from Segments to Consolidated)                     
                (Details)                                                        
56: R40         Business Segments (Reconciliation of Assets from    HTML     36K 
                Segment to Consolidated) (Detail)                                
57: R41         Business Segments - Narratives (Details)            HTML     25K 
58: R42         Revenue (Narratives) (Details)                      HTML     64K 
59: R43         Revenue (Details)                                   HTML     47K 
60: R44         Revenue (Timing of Transfer) (Details)              HTML     44K 
61: R45         Goodwill and Other Intangible Assets (Narrative)    HTML     31K 
                (Details)                                                        
62: R46         Goodwill and Other Intangible Assets (Schedule of   HTML     36K 
                Goodwill) (Details)                                              
63: R47         Goodwill and Other Intangible Assets (Schedule of   HTML     29K 
                Gross Other Intangible Assets) (Details)                         
64: R48         Goodwill and Other Intangible Assets (Schedule of   HTML     54K 
                Intangible Assets) (Details)                                     
65: R49         Goodwill and Other Intangible Assets (Schedule of   HTML     40K 
                Expected Amortization Expense) (Details)                         
66: R50         Accounts Receivable (Details)                       HTML     30K 
67: R51         Inventories (Schedule of Inventory) (Details)       HTML     40K 
68: R52         Property, Plant and Equipment (Details)             HTML     50K 
69: R53         Investments (Narrative) (Details)                   HTML     69K 
70: R54         Investments (Schedule of Variable Interest          HTML     34K 
                Entities) (Details)                                              
71: R55         Investments (Schedule of Direct Financing Future    HTML     30K 
                Minimum Lease Payments for Capital Leases)                       
                (Details)                                                        
72: R56         Long-Term Debt (Schedule of Long-term Debt          HTML     38K 
                Instruments) (Details)                                           
73: R57         Long-Term (Narrative - United States) (Details)     HTML     81K 
74: R58         Long-Term Debt (Narrative - United Kingdom)         HTML     42K 
                (Details)                                                        
75: R59         Fair Value Measurements (Narrative) (Details)       HTML     31K 
76: R60         Fair Value Measurements (Schedule of Fair Value,    HTML     41K 
                Assets and Liabilities Measured on Recurring                     
                Basis) (Details)                                                 
77: R61         Earning Per Common Share (Schedule of Earnings Per  HTML     57K 
                Share, Basic and Diluted) (Details)                              
78: R62         Stock-Based Compensation (Narrative) (Details)      HTML     41K 
79: R63         Stock-Based Compensation (Restricted Stock and      HTML     62K 
                Performance Unit Awards) (Details)                               
80: R64         Retirement Plans (Narrative) (Details)              HTML     43K 
81: R65         Retirement Plans (Schedule Of Net Benefit Costs)    HTML     41K 
                (Details)                                                        
82: R66         Retirement Plans (Schedule of Costs of Retirement   HTML     33K 
                Plans) (Details)                                                 
83: R67         Commitments and Contingent Liabilities (Narrative)  HTML     67K 
                (Details)                                                        
84: R68         Commitments and Contingent Liabilities (Schedule    HTML     30K 
                of Product Warranty Liability) (Details)                         
85: R69         Commitments and Contingent Liabilities              HTML     31K 
                (Environmental Loss Contingencies) (Details)                     
86: R70         Income Taxes (Narrative) (Details)                  HTML     37K 
88: XML         IDEA XML File -- Filing Summary                      XML    156K 
87: EXCEL       IDEA Workbook of Financial Reports                  XLSX     85K 
11: EX-101.INS  XBRL Instance -- fstr-20180331                       XML   1.68M 
13: EX-101.CAL  XBRL Calculations -- fstr-20180331_cal               XML    221K 
14: EX-101.DEF  XBRL Definitions -- fstr-20180331_def                XML    552K 
15: EX-101.LAB  XBRL Labels -- fstr-20180331_lab                     XML   1.36M 
16: EX-101.PRE  XBRL Presentations -- fstr-20180331_pre              XML    868K 
12: EX-101.SCH  XBRL Schema -- fstr-20180331                         XSD    157K 
89: ZIP         XBRL Zipped Folder -- 0000352825-18-000015-xbrl      Zip    193K 


‘XML’   —   IDEA XML File — Filing Summary


This Document is an IDEA XML File.


                                                                                                                                                                                
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4 Subsequent Filings that Reference this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 3/06/24  L.B. Foster Co.                   10-K       12/31/23  128:12M
 3/10/23  L.B. Foster Co.                   10-K       12/31/22  131:14M
 3/02/22  L.B. Foster Co.                   10-K       12/31/21  128:13M
 3/03/21  L.B. Foster Co.                   10-K       12/31/20  130:15M
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