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| | | <HasEmbeddedReports> false </HasEmbeddedReports> |
| | | <LongName> All Reports </LongName> |
| | | <ReportType> Book </ReportType> |
| | | <ShortName> All Reports </ShortName> |
| | | </Report> |
| | </MyReports> |
| <InputFiles> |
| | <File doctype="10-K" original="appn-20191231.htm"> appn-20191231.htm </File> |
| | <File> appn-20191231.xsd </File> |
| | <File> appn-20191231_cal.xml </File> |
| | <File> appn-20191231_def.xml </File> |
| | <File> appn-20191231_lab.xml </File> |
| | <File> appn-20191231_pre.xml </File> |
| | <File> appn12312019ex311.htm </File> |
| | <File> appn12312019ex312.htm </File> |
| | <File> appn12312019ex321.htm </File> |
| | <File> exhibit1015firstamendm.htm </File> |
| | <File> exhibit1016secondamend.htm </File> |
| | <File> exhibit211subsidiaries.htm </File> |
| | <File> exhibit231bdoconsent.htm </File> |
| | <File> exhibit43descriptionof.htm </File> |
| | </InputFiles> |
| <SupplementalFiles> |
| | <File> appn-20191231_g1.jpg </File> |
| | </SupplementalFiles> |
| <BaseTaxonomies> |
| | <BaseTaxonomy> http://xbrl.sec.gov/country/2017-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://fasb.org/us-gaap/2019-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://xbrl.sec.gov/dei/2019-01-31 </BaseTaxonomy> |
| | <BaseTaxonomy> http://fasb.org/srt/2019-01-31 </BaseTaxonomy> |
| | </BaseTaxonomies> |
| <HasPresentationLinkbase> true </HasPresentationLinkbase> |
| <HasCalculationLinkbase> true </HasCalculationLinkbase> |
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