Transfers of Financial Assets Servicing Assets at Amortized Cost Roll Forward (Details) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Beginning Balance	$ 24,336	$ 21,004	$ 24,466	$ 20,698
Additions	2,478	2,947	4,487	4,860
Amortization	(2,106)	(2,005)	(4,245)	(3,612)
Ending Balance	$ 24,708	$ 21,946	$ 24,708	$ 21,946