Securities - Additional Information (Details) $ in Thousands	Dec. 31, 2021 USD ($) Security	Dec. 31, 2020 USD ($) Security	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Schedule Of Investments [Line Items]
Reclassification from other comprehensive income to retained earnings	$ 271,676	$ 191,098
Equity and other securities, at fair value	10,578	$ 8,764
Investment securities with unrealized losses | Security		37
Investment securities posted as collateral	332,300	$ 731,800
Carrying amount of securities pledged as collateral	$ 332,300	$ 323,900
Minimum
Schedule Of Investments [Line Items]
Percentage of shareholders equity for which securities holdings exceeds for no issuer other than U.S. Government and agencies	10.00%	10.00%
Federal Home Loan Bank Advances
Schedule Of Investments [Line Items]
Carrying amount of securities pledged as collateral	$ 0	$ 0
Public Fund Deposits
Schedule Of Investments [Line Items]
Carrying amount of securities pledged as collateral	$ 277,100	$ 245,100
Available-for-sale Securities
Schedule Of Investments [Line Items]
Investment securities with unrealized losses | Security	104
Held-to-maturity Securities
Schedule Of Investments [Line Items]
Investment securities with unrealized losses | Security	0	0
ASU 2016-01
Schedule Of Investments [Line Items]
Reclassification from other comprehensive income to retained earnings			$ 1,400
Equity and other securities, at fair value				$ 6,600
ASU 2017-12
Schedule Of Investments [Line Items]
Reclassification of securities held-to-maturity to securities available-for-sale			$ 94,800