Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Securities available-for-sale	$ 912,429	$ 1,135,317
Total Fair Value
Assets
State tax credits held for sale	39,925	39,046
Obligations of U.S. Government-sponsored enterprises
Assets
Securities available-for-sale	15,161	10,046
Obligations of states and political subdivisions
Assets
Securities available-for-sale	344,232	213,024
Residential mortgage-backed securities
Assets
Securities available-for-sale	526,572	902,021
US Treasury Bill Securities [Member]
Assets
Securities available-for-sale	11,466	10,226
Corporate Debt Securities [Member]
Assets
Securities available-for-sale	14,998
Recurring basis \| Total Fair Value
Assets
Securities available-for-sale	912,429	1,135,317
Other Investments		0
Derivative financial instruments	28,703	11,055
Assets, Fair Value Disclosure	941,132	1,146,372
Liabilities
Derivative financial instruments	34,967	14,747
Total liabilities	34,967	14,747
Recurring basis \| Obligations of U.S. Government-sponsored enterprises \| Total Fair Value
Assets
Securities available-for-sale	15,161	10,046
Recurring basis \| Obligations of states and political subdivisions \| Total Fair Value
Assets
Securities available-for-sale	344,232	213,024
Recurring basis \| Residential mortgage-backed securities \| Total Fair Value
Assets
Securities available-for-sale	526,572	902,021
Recurring basis \| US Treasury Bill Securities [Member] \| Total Fair Value
Assets
Securities available-for-sale	11,466	10,226
Recurring basis \| Corporate Debt Securities [Member] \| Total Fair Value
Assets
Securities available-for-sale	14,998
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available-for-sale	0	0
Other Investments		0
Derivative financial instruments	0	0
Assets, Fair Value Disclosure	0	0
Liabilities
Derivative financial instruments	0	0
Total liabilities	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Obligations of U.S. Government-sponsored enterprises
Assets
Securities available-for-sale	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Obligations of states and political subdivisions
Assets
Securities available-for-sale	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Residential mortgage-backed securities
Assets
Securities available-for-sale	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| US Treasury Bill Securities [Member]
Assets
Securities available-for-sale	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Corporate Debt Securities [Member]
Assets
Securities available-for-sale	0
Recurring basis \| Significant Other Observable Inputs (Level 2)
Assets
Securities available-for-sale	912,429	1,135,317
Other Investments		0
Derivative financial instruments	28,703	11,055
Assets, Fair Value Disclosure	941,132	1,146,372
Liabilities
Derivative financial instruments	34,967	14,747
Total liabilities	34,967	14,747
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Obligations of U.S. Government-sponsored enterprises
Assets
Securities available-for-sale	15,161	10,046
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Obligations of states and political subdivisions
Assets
Securities available-for-sale	344,232	213,024
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Residential mortgage-backed securities
Assets
Securities available-for-sale	526,572	902,021
Recurring basis \| Significant Other Observable Inputs (Level 2) \| US Treasury Bill Securities [Member]
Assets
Securities available-for-sale	11,466	10,226
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Corporate Debt Securities [Member]
Assets
Securities available-for-sale	14,998
Recurring basis \| Significant Unobservable Inputs (Level 3)
Assets
Securities available-for-sale	0	0
Other Investments		0
Derivative financial instruments	0	0
Assets, Fair Value Disclosure	0	0
Liabilities
Derivative financial instruments	0	0
Total liabilities	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Obligations of U.S. Government-sponsored enterprises
Assets
Securities available-for-sale	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Obligations of states and political subdivisions
Assets
Securities available-for-sale	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Residential mortgage-backed securities
Assets
Securities available-for-sale	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| US Treasury Bill Securities [Member]
Assets
Securities available-for-sale	0	$ 0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Corporate Debt Securities [Member]
Assets
Securities available-for-sale	$ 0

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Fair value of financial and nonfinancial obligations.

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