Fair Value of Assets and Liabilities - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 5,294	$ 3,168
Change included in earnings	(34)	76
Purchases and issuances	3,942	5,653
Sales and settlements	(2,343)	(4,805)
Ending balance	6,859	4,092
Net change in unrealized gains (losses) relating to items held at end of period	1,534	1,858
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	4,157	1,654
Change included in earnings	282	(112)
Purchases and issuances	886	692
Sales and settlements	0	0
Ending balance	5,325	2,234
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	1,137	1,514
Change included in earnings	(316)	188
Purchases and issuances	3,056	4,961
Sales and settlements	(2,343)	(4,805)
Ending balance	1,534	1,858
Net change in unrealized gains (losses) relating to items held at end of period	$ 1,534	$ 1,858