XML 71 R40.htm IDEA: XBRL DOCUMENT v3.19.2
Summary of Significant Accounting Policies - Principles of Consolidation (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Accounting Policies [Abstract]      
Other comprehensive income $ 0 $ 0 $ 0