Mortgage Banking Activities, Mortgage Servicing Rights (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced for others	113,217		113,217		102,008
Outstanding principal balance of residential mortgage loans serviced for others	$ 19,327,944,000		$ 19,327,944,000		$ 16,442,446,000
Weighted average interest rate	3.52%		3.52%		3.58%
Remaining term (in months)			285 months		281 months
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 209,563,000	$ 132,915,000	$ 163,198,000	$ 101,172,000	$ 101,172,000
Additions	5,754,000	7,937,000	10,969,000	17,767,000
Acquisitions	44,867,000	0	44,867,000	0
Changes due to principal payments	(7,357,000)	(10,182,000)	(15,317,000)	(22,143,000)
Change in fair value due to market assumption changes	17,485,000	(13,041,000)	66,595,000	20,833,000
Ending balance	$ 270,312,000	$ 117,629,000	$ 270,312,000	$ 117,629,000	$ 163,198,000
Servicing Assets at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Discount rate - risk-free rate plus a market premium (in hundredths)			8.77%		8.39%
Prepayment rate - based upon loan interest rate, original term and loan type			7.88%		12.11%
Loan servicing costs - annually per loan based upon loan type, performing, minimum (in dollars per loan)			$ 69		$ 69
Loan servicing costs - annually per loan based upon loan type, performing, maximum (in dollars per loan)			94		94
Loan servicing costs - annually per loan based upon loan type, delinquent, minimum (in dollars per loan)			150		150
Loan servicing costs - annually per loan based upon loan type, delinquent, maximum (in dollars per loan)			500		500
Loan servicing costs - annually per loan based upon loan type, foreclosure, minimum (in dollars per loan)			1,000		1,000
Loan servicing costs - annually per loan based upon loan type, foreclosure, maximum (in dollars per loan)			$ 4,000		$ 4,000
Escrow earnings rate - indexed to rates paid on deposit accounts with comparable average life (in hundredths)			3.05%		1.32%
Primary secondary mortgage rate spread	105		105		105
Delinquency rate			1.87%		2.05%