Fair Value Measurements - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 12,829	$ 8,178
Change included in earnings	(1,026)	(426)
Purchases and issuances	4,243	4,444
Sales and settlements	(2,508)	(2,834)
Ending balance	13,538	9,362
Net change in unrealized gains (losses) relating to items held at end of period	1,237	1,323
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	978	873
Change included in earnings	(329)	(400)
Purchases and issuances	3,096	3,684
Sales and settlements	(2,508)	(2,834)
Ending balance	1,237	1,323
Net change in unrealized gains (losses) relating to items held at end of period	1,237	1,323
Commercial servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,030
Change included in earnings	(23)
Purchases and issuances	40
Sales and settlements	0
Ending balance	1,047
Net change in unrealized gains (losses) relating to items held at end of period	0
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	10,821	7,305
Change included in earnings	(674)	(26)
Purchases and issuances	1,107	760
Sales and settlements	0	0
Ending balance	11,254	8,039
Net change in unrealized gains (losses) relating to items held at end of period	$ 0	$ 0