Loans and Leases - Allowance for Loan and Lease Losses and Recorded Investment in Loans and Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	$ 1,089			$ 356
Ending balance: pooled	70,922			70,999
Financing Receivable, Allowance for Credit Loss	72,011	$ 68,286	$ 71,924	71,355	$ 71,497	$ 83,044
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	13,142			33,498
Ending balance: pooled	5,648,635			5,293,697
Loans measured at fair value	0			118
Total loans and leases held for investment	5,661,777		5,310,017	5,327,313
Commercial Financial And Agricultural [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			333
Ending balance: pooled	13,004			11,401
Financing Receivable, Allowance for Credit Loss	13,004	11,840	13,536	11,734	10,233	13,584
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	448			1,246
Ending balance: pooled	1,027,906			919,375
Loans measured at fair value	0			0
Total loans and leases held for investment	1,028,354		956,396	920,621
Paycheck Protection Program Loans
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	0			3
Financing Receivable, Allowance for Credit Loss	0	1	2	3	0	0
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	5,358			252,849
Loans measured at fair value	0			0
Total loans and leases held for investment	5,358		31,748	252,849
Real-Estate Commercial [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	1,089			0
Ending balance: pooled	40,589			43,194
Financing Receivable, Allowance for Credit Loss	41,678	40,426	41,095	43,194	45,459	52,230
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	9,137			26,264
Ending balance: pooled	2,861,149			2,574,537
Loans measured at fair value	0			118
Total loans and leases held for investment	2,870,286		2,718,535	2,600,919
Real-Estate Construction [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	4,223			3,649
Financing Receivable, Allowance for Credit Loss	4,223	3,634	4,575	3,649	2,799	3,298
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	319,449			274,529
Loans measured at fair value	0			0
Total loans and leases held for investment	319,449		283,918	274,529
Real Estate Residential Secured For Business Purpose [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	6,420			6,747
Financing Receivable, Allowance for Credit Loss	6,420	6,202	6,482	6,747	6,692	7,317
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	961			3,045
Ending balance: pooled	418,691			404,619
Loans measured at fair value	0			0
Total loans and leases held for investment	419,652		409,900	407,664
Real Estate Residential Secured For Personal Purpose [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			23
Ending balance: pooled	2,937			2,597
Financing Receivable, Allowance for Credit Loss	2,937	2,592	2,403	2,620	3,056	3,055
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	2,202			2,160
Ending balance: pooled	626,942			511,170
Loans measured at fair value	0			0
Total loans and leases held for investment	629,144		540,566	513,330
Real Estate Home Equity Secured For Personal Purpose [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	1,074			1,124
Financing Receivable, Allowance for Credit Loss	1,074	976	1,028	1,124	1,257	1,176
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	394			783
Ending balance: pooled	168,142			159,235
Loans measured at fair value	0			0
Total loans and leases held for investment	168,536		158,909	160,018
Loans to Individuals [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	376			319
Financing Receivable, Allowance for Credit Loss	376	369	363	319	447	533
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	27,061			25,845
Loans measured at fair value	0			0
Total loans and leases held for investment	27,061		25,504	25,845
Lease Financings [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	2,299			1,815
Financing Receivable, Allowance for Credit Loss	2,299	2,246	2,290	1,815	1,404	1,701
Loans and leases held for investment [Abstract]
Ending balance: individually analyzed	0			0
Ending balance: pooled	193,937			171,538
Loans measured at fair value	0			0
Total loans and leases held for investment	193,937		184,541	171,538
Unallocated [Member]
Allowance For Credit Losses, Loans And Leases [Abstract]
Ending balance: pooled	0			150
Financing Receivable, Allowance for Credit Loss	$ 0	$ 0	$ 150	$ 150	$ 150	$ 150