Mortgage Banking Activities Mortgage Banking Activities, Mortgage Banking Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Mortgage Banking Revenue [Abstract]
Net realized gains on sale of mortgage loans	$ 11,787	$ 15,865	$ 20,402	$ 24,314
Net change in unrealized gain on mortgage loans held for sale	985	3,884	4,827	7,167
Net change in the fair value of mortgage loan commitments	(3,274)	5,329	1,260	17,365
Net change in the fair value of forward sales contracts	4,342	(5,992)	(4,106)	(13,113)
Total production revenue	13,840	19,086	22,383	35,733
Servicing revenue	16,436	15,798	33,084	31,251
Total mortgage banking revenue	$ 30,276	$ 34,884	$ 55,467	$ 66,984