Fair Value Measurements - Reconciliation of Assets with Unobservable Inputs (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 16,041,000	$ 13,538,000	$ 13,944,000	$ 12,829,000
Change included in earnings	(4,228,000)	(1,574,000)	(6,076,000)	(2,600,000)
Purchases and issuances	18,621,000	5,653,000	26,798,000	9,896,000
Sales and settlements	(13,898,000)	(3,710,000)	(18,130,000)	(6,218,000)
Ending balance	16,536,000	13,907,000	16,536,000	13,907,000
Net change in unrealized gains (losses) relating to items held at end of period	4,653,000	2,072,000	4,653,000	2,072,000
Net change in unrealized gains (losses) included in other comprehensive income	0	0	0	0
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3,188,000	1,237,000	810,000	978,000
Change included in earnings	(2,242,000)	(549,000)	(3,139,000)	(878,000)
Purchases and issuances	17,605,000	5,094,000	25,112,000	8,190,000
Sales and settlements	(13,898,000)	(3,710,000)	(18,130,000)	(6,218,000)
Ending balance	4,653,000	2,072,000	4,653,000	2,072,000
Net change in unrealized gains (losses) relating to items held at end of period	4,653,000	2,072,000	4,653,000	2,072,000
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	11,653,000	11,254,000	11,920,000	10,821,000
Change included in earnings	(1,928,000)	(950,000)	(2,858,000)	(1,624,000)
Purchases and issuances	996,000	532,000	1,659,000	1,639,000
Sales and settlements	0	0	0	0
Ending balance	10,721,000	10,836,000	10,721,000	10,836,000
Net change in unrealized gains (losses) relating to items held at end of period	0	0	0	0
Commercial servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,200,000	1,047,000	1,214,000	1,030,000
Change included in earnings	(58,000)	(75,000)	(79,000)	(98,000)
Purchases and issuances	20,000	27,000	27,000	67,000
Sales and settlements	0	0	0	0
Ending balance	1,162,000	999,000	1,162,000	999,000
Net change in unrealized gains (losses) relating to items held at end of period	$ 0	$ 0	$ 0	$ 0