XML 108 R92.htm IDEA: XBRL DOCUMENT v3.8.0.1
Servicing Assets - Additional Information (Details) - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Transfers And Servicing [Abstract]      
Servicing fees $ 3,658,000 $ 1,906,000 $ 0