Fair Value Measurements - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 3,168	$ 1,851
Change included in earnings	(2,589)	(2,428)
Purchases and issuances	23,641	21,688
Sales and settlements	(18,926)	(17,943)
Ending balance	5,294	3,168
Net change in unrealized gains (losses) relating to items held at end of period	1,137	1,514
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,654	1,010
Change included in earnings	(526)	(158)
Purchases and issuances	3,029	802
Sales and settlements	0	0
Ending balance	4,157	1,654
Net change in unrealized gains (losses) relating to items held at end of period	0	0
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,514	841
Change included in earnings	(2,063)	(2,270)
Purchases and issuances	20,612	20,886
Sales and settlements	(18,926)	(17,943)
Ending balance	1,137	1,514
Net change in unrealized gains (losses) relating to items held at end of period	$ 1,137	$ 1,514