Fair Value Measurements - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 26,562,000	$ 13,944,000
Change included in earnings	(2,179,000)	(1,848,000)
Purchases and issuances	20,756,000	8,177,000
Sales and settlements	(9,442,000)	(4,232,000)
Ending balance	35,697,000	16,041,000
Net change in unrealized gains (losses) relating to items held at end of period	2,619,000	3,188,000
Net change in unrealized gains (losses) included in other comprehensive income	0	0
Held to maturity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	10,000,000
Change included in earnings	0
Purchases and issuances	10,000,000
Sales and settlements	0
Ending balance	20,000,000
Net change in unrealized gains (losses) relating to items held at end of period	(94,000)
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	11,218,000	11,920,000
Change included in earnings	(1,009,000)	(930,000)
Purchases and issuances	1,448,000	663,000
Sales and settlements	0	0
Ending balance	11,657,000	11,653,000
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	1,310,000	1,214,000
Change included in earnings	(23,000)	(21,000)
Purchases and issuances	40,000	7,000
Sales and settlements	0	0
Ending balance	1,327,000	1,200,000
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	4,034,000	810,000
Change included in earnings	(1,147,000)	(897,000)
Purchases and issuances	9,268,000	7,507,000
Sales and settlements	(9,442,000)	(4,232,000)
Ending balance	2,713,000	3,188,000
Net change in unrealized gains (losses) relating to items held at end of period	$ 2,713,000	$ 3,188,000