Fair Value Measurements - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 13,538	$ 9,362	$ 12,829	$ 8,178
Change included in earnings	(1,574)	(720)	(2,600)	(1,146)
Purchases and issuances	5,653	6,612	9,896	11,056
Sales and settlements	(3,710)	(5,104)	(6,218)	(7,938)
Ending balance	13,907	10,150	13,907	10,150
Net change in unrealized gains (losses) relating to items held at end of period	2,072	1,417	2,072	1,417
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,237	1,323	978	873
Change included in earnings	(549)	(602)	(878)	(1,002)
Purchases and issuances	5,094	5,800	8,190	9,484
Sales and settlements	(3,710)	(5,104)	(6,218)	(7,938)
Ending balance	2,072	1,417	2,072	1,417
Net change in unrealized gains (losses) relating to items held at end of period	2,072	1,417	2,072	1,417
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	11,254	8,039	10,821	7,305
Change included in earnings	(950)	(118)	(1,624)	(144)
Purchases and issuances	532	812	1,639	1,572
Sales and settlements	0	0	0	0
Ending balance	10,836	8,733	10,836	8,733
Net change in unrealized gains (losses) relating to items held at end of period	0	$ 0	0	$ 0
Commercial servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,047		1,030
Change included in earnings	(75)		(98)
Purchases and issuances	27		67
Sales and settlements	0		0
Ending balance	999		999
Net change in unrealized gains (losses) relating to items held at end of period	$ 0		$ 0