XML 71 R56.htm IDEA: XBRL DOCUMENT v3.19.1
Summary of Significant Accounting Policies - Intangible Assets (Details)
12 Months Ended
Dec. 31, 2018
Minimum  
Finite-Lived Intangible Assets [Line Items]  
Intangible asset, estimated period of benefit 1 year
Maximum  
Finite-Lived Intangible Assets [Line Items]  
Intangible asset, estimated period of benefit 15 years
Maximum | Capitalized software development  
Finite-Lived Intangible Assets [Line Items]  
Intangible asset, estimated period of benefit 2 years