Fair Value Measurements - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 13,944,000	$ 12,829,000
Change included in earnings	(1,848,000)	(1,026,000)
Purchases and issuances	8,177,000	4,243,000
Sales and settlements	(4,232,000)	(2,508,000)
Ending balance	16,041,000	13,538,000
Net change in unrealized gains (losses) relating to items held at end of period	3,188,000	1,237,000
Net change in unrealized gains (losses) included in other comprehensive income	0	0
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	810,000	978,000
Change included in earnings	(897,000)	(329,000)
Purchases and issuances	7,507,000	3,096,000
Sales and settlements	(4,232,000)	(2,508,000)
Ending balance	3,188,000	1,237,000
Net change in unrealized gains (losses) relating to items held at end of period	3,188,000	1,237,000
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	11,920,000	10,821,000
Change included in earnings	(930,000)	(674,000)
Purchases and issuances	663,000	1,107,000
Sales and settlements	0	0
Ending balance	11,653,000	11,254,000
Net change in unrealized gains (losses) relating to items held at end of period	0	0
Commercial servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,214,000	1,030,000
Change included in earnings	(21,000)	(23,000)
Purchases and issuances	7,000	40,000
Sales and settlements	0	0
Ending balance	1,200,000	1,047,000
Net change in unrealized gains (losses) relating to items held at end of period	$ 0	$ 0