Mortgage Banking Activities Mortgage Banking Activities, Mortgage Banking Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Mortgage Banking Revenue [Abstract]
Net realized gains on sale of mortgage loans	$ 24,109	$ 10,174	$ 33,826	$ 15,867
Net change in unrealized gain on mortgage loans held for sale	5,024	921	8,585	868
Net change in the fair value of mortgage loan commitments	3,381	1,506	22,398	4,219
Net change in the fair value of forward sales contracts	6,671	(732)	(4,054)	(1,217)
Total production revenue	39,185	11,869	60,755	19,737
Servicing revenue	14,751	16,262	30,348	32,228
Total mortgage banking revenue	$ 53,936	$ 28,131	$ 91,103	$ 51,965