Loans and Allowance for Credit Losses (Allowance for Credit Losses by Portfolio Class) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			$ 318,882	$ 307,907
Allowance for loan losses: Net provision for loan losses	$ 14,925	$ 8,723	25,387	21,691
Allowance for loan losses: Ending balance	313,189	316,148	313,189	316,148
Reserve for unfunded lending commitments: Beginning balance			24,053	28,894
Reserve for unfunded lending commitments: Provision for losses			3,047	(2,815)
Reserve for unfunded lending commitments: Ending balance	27,100	26,079	27,100	26,079
Total allowance for credit losses	340,289	342,227	340,289	342,227
Allowance for credit losses: Individually evaluated	10,618	530	10,618	530
Allowance for credit losses: Collectively evaluated	329,671	341,697	329,671	341,697
Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(35,621)	(35,317)
Allowance for loan losses: Recoveries			7,588	19,052
Allowance for loan losses: Net provision for loan losses			22,340	24,506
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			71,975	74,539
Allowance for loan losses: Ending balance	65,335	77,643	65,335	77,643
Reserve for unfunded lending commitments: Beginning balance			642	1,344
Reserve for unfunded lending commitments: Provision for losses			(152)	(376)
Reserve for unfunded lending commitments: Ending balance	490	968	490	968
Total allowance for credit losses	65,825	78,611	65,825	78,611
Allowance for credit losses: Collectively evaluated	65,825	78,611	65,825	78,611
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			21,158	27,039
Allowance for loan losses: Ending balance	17,685	27,271	17,685	27,271
Reserve for unfunded lending commitments: Beginning balance			14,639	20,019
Reserve for unfunded lending commitments: Provision for losses			1,483	(2,693)
Reserve for unfunded lending commitments: Ending balance	16,122	17,326	16,122	17,326
Total allowance for credit losses	33,807	44,597	33,807	44,597
Allowance for credit losses: Collectively evaluated	33,807	44,597	33,807	44,597
Total Commercial [Member] | Non-Purchased Credit Impaired Loans [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(34)	(8,819)
Allowance for loan losses: Recoveries				5
Allowance for loan losses: Net provision for loan losses			(6,606)	11,918
Total Commercial [Member] | Non-Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(33)	(225)
Allowance for loan losses: Recoveries			123	62
Allowance for loan losses: Net provision for loan losses			(3,563)	395
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			157,354	141,934
Allowance for loan losses: Ending balance	160,314	144,438	160,314	144,438
Reserve for unfunded lending commitments: Beginning balance			6,750	5,834
Reserve for unfunded lending commitments: Provision for losses			1,996	336
Reserve for unfunded lending commitments: Ending balance	8,746	6,170	8,746	6,170
Total allowance for credit losses	169,060	150,608	169,060	150,608
Allowance for credit losses: Individually evaluated	9,667	530	9,667	530
Allowance for credit losses: Collectively evaluated	159,393	150,078	159,393	150,078
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			121,090	101,737
Allowance for loan losses: Ending balance	122,601	105,873	122,601	105,873
Reserve for unfunded lending commitments: Beginning balance			6,441	5,507
Reserve for unfunded lending commitments: Provision for losses			1,963	355
Reserve for unfunded lending commitments: Ending balance	8,404	5,862	8,404	5,862
Total allowance for credit losses	131,005	111,735	131,005	111,735
Allowance for credit losses: Individually evaluated	9,626	474	9,626	474
Allowance for credit losses: Collectively evaluated	121,379	111,261	121,379	111,261
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			36,264	40,197
Allowance for loan losses: Ending balance	37,713	38,565	37,713	38,565
Reserve for unfunded lending commitments: Beginning balance			309	327
Reserve for unfunded lending commitments: Provision for losses			33	(19)
Reserve for unfunded lending commitments: Ending balance	342	308	342	308
Total allowance for credit losses	38,055	38,873	38,055	38,873
Allowance for credit losses: Individually evaluated	41	56	41	56
Allowance for credit losses: Collectively evaluated	38,014	38,817	38,014	38,817
Total Commercial [Member] | Total Commercial And Industrial [Member] | Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(27,225)	(17,304)
Allowance for loan losses: Recoveries			5,405	16,915
Allowance for loan losses: Net provision for loan losses			24,780	2,893
Total Commercial [Member] | Total Commercial And Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(24,484)	(17,304)
Allowance for loan losses: Recoveries			5,042	16,054
Allowance for loan losses: Net provision for loan losses			20,953	5,386
Total Commercial [Member] | Total Commercial And Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Commercial Real Estate - Owner Occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(2,741)
Allowance for loan losses: Recoveries			363	861
Allowance for loan losses: Net provision for loan losses			3,827	(2,493)
Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			42,445	38,983
Allowance for loan losses: Ending balance	43,617	41,693	43,617	41,693
Reserve for unfunded lending commitments: Beginning balance			4	30
Reserve for unfunded lending commitments: Provision for losses			(3)	(19)
Reserve for unfunded lending commitments: Ending balance	1	11	1	11
Total allowance for credit losses	43,618	41,704	43,618	41,704
Allowance for credit losses: Individually evaluated	753		753
Allowance for credit losses: Collectively evaluated	42,865	41,704	42,865	41,704
Residential Mortgages [Member] | Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(429)	(67)
Allowance for loan losses: Recoveries			453	296
Allowance for loan losses: Net provision for loan losses			1,148	2,481
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			25,950	25,412
Allowance for loan losses: Ending balance	26,238	25,103	26,238	25,103
Reserve for unfunded lending commitments: Beginning balance			2,018	1,667
Reserve for unfunded lending commitments: Provision for losses			(277)	(63)
Reserve for unfunded lending commitments: Ending balance	1,741	1,604	1,741	1,604
Total allowance for credit losses	27,979	26,707	27,979	26,707
Allowance for credit losses: Individually evaluated	198		198
Allowance for credit losses: Collectively evaluated	$ 27,781	$ 26,707	27,781	26,707
Consumer [Member] | Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(7,900)	(8,902)
Allowance for loan losses: Recoveries			1,607	1,774
Allowance for loan losses: Net provision for loan losses			$ 6,581	$ 6,819