Allowance for Credit Losses - Schedule of Loan Portfolio, Excluding PCI Loans and Related Allowance (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Recorded Investment
Individually Evaluated	$ 49,601	$ 49,196
Collectively Evaluated	5,611,891	5,686,153
Total	5,661,492	5,735,349
Associated Allowance
Individually Evaluated	6,312	7,708
Collectively Evaluated	80,331	85,025
Total	86,643	92,733	$ 85,411	$ 35,154
Construction and land development
Recorded Investment
Individually Evaluated	261	276
Collectively Evaluated	226,856	244,832
Total	227,117	245,108
Associated Allowance
Individually Evaluated	11	13
Collectively Evaluated	4,417	4,907
Total	4,428	4,920	4,646	1,842
Commercial real estate - owner-occupied
Recorded Investment
Individually Evaluated	9,209	10,243
Collectively Evaluated	1,123,876	1,131,067
Total	1,133,085	1,141,310
Associated Allowance
Individually Evaluated	422	402
Collectively Evaluated	9,370	9,466
Total	9,792	9,868	5,327	5,361
Commercial real estate - non owner-occupied
Recorded Investment
Individually Evaluated	7,871	8,083
Collectively Evaluated	1,430,494	1,387,771
Total	1,438,365	1,395,854
Associated Allowance
Individually Evaluated	1,746	1,640
Collectively Evaluated	34,483	36,626
Total	36,229	38,266	35,643	7,863
Residential real estate
Recorded Investment
Individually Evaluated	19,057	16,506
Collectively Evaluated	1,227,492	1,326,122
Total	1,246,549	1,342,628
Associated Allowance
Individually Evaluated	1,280	2,064
Collectively Evaluated	13,073	15,436
Total	14,353	17,500	19,899	7,667
Commercial and financial
Recorded Investment
Individually Evaluated	12,536	13,281
Collectively Evaluated	848,277	841,472
Total	860,813	854,753
Associated Allowance
Individually Evaluated	2,749	3,498
Collectively Evaluated	16,167	15,192
Total	18,916	18,690	15,470	9,716
Consumer
Recorded Investment
Individually Evaluated	667	807
Collectively Evaluated	173,243	187,928
Total	173,910	188,735
Associated Allowance
Individually Evaluated	104	91
Collectively Evaluated	2,821	3,398
Total	2,925	3,489	$ 4,426	$ 2,705
Paycheck Protection Program
Recorded Investment
Individually Evaluated	0	0
Collectively Evaluated	581,653	566,961
Total	581,653	566,961
Associated Allowance
Individually Evaluated	0	0
Collectively Evaluated	0	0
Total	$ 0	$ 0

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount, before allowance for credit loss, of financing receivable.

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