Liability for Losses Under Representations and Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
During the year:
Balance at beginning of year	$ 20,053	$ 19,067	$ 20,611
Provision for losses on mortgage loans sold resulting from sales of mortgage loans	5,824	5,890	7,090
Provision for losses on mortgage loans sold reduction in liability due to change in estimate	(4,672)	(4,301)	(7,672)
(Incurred losses) recoveries, net	(50)	(603)	(962)
Balance at end of year	21,155	20,053	$ 19,067
Unpaid principal balance of mortgage loans subject to representations and warranties at end of year	$ 137,849,704	$ 120,855,101