Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Securities available for sale	$ 1,219,814	$ 912,429
Estimate of Fair Value Measurement [Member]
Assets
Other investments	59,156	48,764
State tax credits held for sale	41,306	39,925
Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	114,937	15,161
Obligations of states and political subdivisions
Assets
Securities available for sale	515,416	344,232
Agency mortgage-backed securities
Assets
Securities available for sale	505,766	526,572
U.S. Treasury bills
Assets
Securities available for sale	71,292	11,466
Corporate debt securities
Assets
Securities available for sale	12,403	14,998
Recurring basis \| Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	1,219,814	912,429
Other investments	2,999
Derivatives	17,442	28,703
Total assets	1,240,255	941,132
Liabilities
Derivatives	21,428	34,967
Total liabilities	21,428	34,967
Recurring basis \| Obligations of U.S. Government-sponsored enterprises \| Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	114,937	15,161
Recurring basis \| Obligations of states and political subdivisions \| Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	515,416	344,232
Recurring basis \| Agency mortgage-backed securities \| Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	505,766	526,572
Recurring basis \| U.S. Treasury bills \| Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	71,292	11,466
Recurring basis \| Corporate debt securities \| Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	12,403	14,998
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Other investments	217
Derivatives	0	0
Total assets	217	0
Liabilities
Derivatives	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) \| Agency mortgage-backed securities
Assets
Securities available for sale	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| U.S. Treasury bills
Assets
Securities available for sale	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Corporate debt securities
Assets
Securities available for sale	0	0
Recurring basis \| Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	1,219,814	912,429
Other investments	2,782
Derivatives	17,442	28,703
Total assets	1,240,038	941,132
Liabilities
Derivatives	21,428	34,967
Total liabilities	21,428	34,967
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	114,937	15,161
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Obligations of states and political subdivisions
Assets
Securities available for sale	515,416	344,232
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Agency mortgage-backed securities
Assets
Securities available for sale	505,766	526,572
Recurring basis \| Significant Other Observable Inputs (Level 2) \| U.S. Treasury bills
Assets
Securities available for sale	71,292	11,466
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Corporate debt securities
Assets
Securities available for sale	12,403	14,998
Recurring basis \| Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Other investments	0
Derivatives	0	0
Total assets	0	0
Liabilities
Derivatives	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) \| Agency mortgage-backed securities
Assets
Securities available for sale	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| U.S. Treasury bills
Assets
Securities available for sale	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Corporate debt securities
Assets
Securities available for sale	$ 0	$ 0

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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