Loans and Allowance for Credit Losses - Textual (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($) loan	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($) loan	Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 15,110,344,000		$ 15,110,344,000		$ 12,012,503,000
Non-credit related discount			31,800,000		21,500,000
Financing receivable, accrued interest excluded from amortized costs	46,500,000		46,500,000		39,800,000
Nonaccrual loans with no allowance for credit loss	$ 11,800,000		$ 11,800,000		14,500,000
Number of loan modifications | loan	1	1	1	1
Balance prior to TDR	$ 13,000	$ 784,000	$ 13,000	$ 784,000
Foreclosed assets and other real estate owned	4,084,000		4,084,000		6,032,000
Financing receivable, collateral dependent, amount	97,493,000		97,493,000		47,089,000
Unfunded commitments, allowance for credit loss	25,900,000		25,900,000		22,400,000
Off-balance sheet, credit loss, liability, credit loss expense (reversal)	3,500,000	$ 0	3,500,000	$ 0
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process of foreclosure, amount	2,420,000		2,420,000		1,806,000
OREO Received in Full or Partial Satisfaction of Loans | Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosed assets and other real estate owned	524,000		524,000		831,000
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 11,522,685,000		$ 11,522,685,000		9,167,250,000
Number of loan modifications | loan	1	1	1	1
Balance prior to TDR	$ 13,000	$ 784,000	$ 13,000	$ 784,000
Real Estate | OREO Received in Full or Partial Satisfaction of Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance prior to TDR	0	$ 0	0	$ 0
Paycheck Protection Program Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	19,500,000		19,500,000		116,700,000
Other commercial | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 7,082,055,000		$ 7,082,055,000		5,738,904,000
Number of loan modifications | loan	1		1
Balance prior to TDR	$ 13,000		$ 13,000
Financing receivable, collateral dependent, amount	84,094,000		84,094,000		32,849,000
Single family residential | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,357,942,000		2,357,942,000		2,101,975,000
Number of loan modifications | loan		1		1
Balance prior to TDR		$ 784,000		$ 784,000
Allowance for credit losses on loans		$ 5,100		$ 5,100
Financing receivable, collateral dependent, amount	$ 1,944,000		$ 1,944,000		$ 1,838,000
Commercial real estate | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans with subsequent default | loan			0
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term of loan			1 year
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term of loan			3 years