Fair Value of Assets and Liabilities - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 6,859	$ 4,092	$ 5,294	$ 3,168
Change included in earnings	(150)	(855)	(184)	(1,415)
Purchases and issuances	4,996	6,640	8,938	11,748
Sales and settlements	(4,540)	(4,695)	(6,883)	(8,319)
Ending balance	7,165	5,182	7,165	5,182
Net change in unrealized gains (losses) relating to items held at end of period	1,337	2,580	1,337	2,580
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	5,325	2,234	4,157	1,654
Change included in earnings	(48)	(245)	234	(357)
Purchases and issuances	551	613	1,437	1,305
Sales and settlements	0	0	0	0
Ending balance	5,828	2,602	5,828	2,602
Net change in unrealized gains (losses) relating to items held at end of period	0	0	0	0
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,534	1,858	1,137	1,514
Change included in earnings	(102)	(610)	(418)	(1,058)
Purchases and issuances	4,445	6,027	7,501	10,443
Sales and settlements	(4,540)	(4,695)	(6,883)	(8,319)
Ending balance	1,337	2,580	1,337	2,580
Net change in unrealized gains (losses) relating to items held at end of period	$ 1,337	$ 2,580	$ 1,337	$ 2,580