Loans, Changes in the Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ 40,891
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			38,776	$ 39,776	$ 39,776
Provision for credit losses			(4,000)		(1,000)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	$ 34,776		34,776		38,776
Allowance for credit losses on loans
Charge offs			40,891
Provision for credit losses	21,943	$ 16,998	62,014	13,006
Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			312,720	280,015	280,015
Charge offs			(40,891)		(10,146)
Recoveries			7,965		8,852
Net Charge offs			(32,925)		(1,294)
Provision for credit losses			66,000		34,000
Financing Receivable, Allowance for Credit Loss, Ending Balance	345,795		345,795		312,720
Allowance for credit losses on loans
Charge offs			(40,891)		(10,146)
Recoveries			7,965		8,852
Net Charge offs			(32,925)		(1,294)
Allowance for Loan Losses [Member] | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			119,076	89,857	89,857
Charge offs			(31,816)		(4,491)
Recoveries			2,322		5,282
Net Charge offs			(29,494)		791
Provision for credit losses			34,710		28,428
Financing Receivable, Allowance for Credit Loss, Ending Balance	124,292		124,292		119,076
Allowance for credit losses on loans
Charge offs			(31,816)		(4,491)
Recoveries			2,322		5,282
Net Charge offs			(29,494)		791
Allowance for Loan Losses [Member] | Commercial real estate — owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			9,475	11,473	11,473
Charge offs			0		0
Recoveries			8		13
Net Charge offs			8		13
Provision for credit losses			1,976		(2,011)
Financing Receivable, Allowance for Credit Loss, Ending Balance	11,459		11,459		9,475
Allowance for credit losses on loans
Charge offs			0		0
Recoveries			8		13
Net Charge offs			8		13
Allowance for Loan Losses [Member] | Commercial and business lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			128,551	101,330	101,330
Charge offs			(31,816)		(4,491)
Recoveries			2,329		5,295
Net Charge offs			(29,487)		804
Provision for credit losses			36,686		26,418
Financing Receivable, Allowance for Credit Loss, Ending Balance	135,751		135,751		128,551
Allowance for credit losses on loans
Charge offs			(31,816)		(4,491)
Recoveries			2,329		5,295
Net Charge offs			(29,487)		804
Allowance for Loan Losses [Member] | Commercial real estate — investor
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			54,398	72,803	72,803
Charge offs			(242)		(50)
Recoveries			2,789		50
Net Charge offs			2,547		0
Provision for credit losses			10,520		(18,405)
Financing Receivable, Allowance for Credit Loss, Ending Balance	67,466		67,466		54,398
Allowance for credit losses on loans
Charge offs			(242)		(50)
Recoveries			2,789		50
Net Charge offs			2,547		0
Allowance for Loan Losses [Member] | Real estate construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			45,589	37,643	37,643
Charge offs			(25)		(48)
Recoveries			42		106
Net Charge offs			18		58
Provision for credit losses			6,128		7,887
Financing Receivable, Allowance for Credit Loss, Ending Balance	51,734		51,734		45,589
Allowance for credit losses on loans
Charge offs			(25)		(48)
Recoveries			42		106
Net Charge offs			18		58
Allowance for Loan Losses [Member] | Commercial real estate lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			99,986	110,446	110,446
Charge offs			(266)		(98)
Recoveries			2,831		156
Net Charge offs			2,565		58
Provision for credit losses			16,648		(10,518)
Financing Receivable, Allowance for Credit Loss, Ending Balance	119,200		119,200		99,986
Allowance for credit losses on loans
Charge offs			(266)		(98)
Recoveries			2,831		156
Net Charge offs			2,565		58
Allowance for Loan Losses [Member] | Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			228,538	211,776	211,776
Charge offs			(32,082)		(4,588)
Recoveries			5,161		5,451
Net Charge offs			(26,921)		862
Provision for credit losses			53,334		15,900
Financing Receivable, Allowance for Credit Loss, Ending Balance	254,951		254,951		228,538
Allowance for credit losses on loans
Charge offs			(32,082)		(4,588)
Recoveries			5,161		5,451
Net Charge offs			(26,921)		862
Allowance for Loan Losses [Member] | Residential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			38,298	40,787	40,787
Charge offs			(714)		(567)
Recoveries			357		908
Net Charge offs			(358)		341
Provision for credit losses			2,496		(2,830)
Financing Receivable, Allowance for Credit Loss, Ending Balance	40,437		40,437		38,298
Allowance for credit losses on loans
Charge offs			(714)		(567)
Recoveries			357		908
Net Charge offs			(358)		341
Allowance for Loan Losses [Member] | Auto finance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			19,619	1,999	1,999
Charge offs			(4,056)		(1,041)
Recoveries			783		98
Net Charge offs			(3,273)		(943)
Provision for credit losses			6,654		18,563
Financing Receivable, Allowance for Credit Loss, Ending Balance	23,000		23,000		19,619
Allowance for credit losses on loans
Charge offs			(4,056)		(1,041)
Recoveries			783		98
Net Charge offs			(3,273)		(943)
Allowance for Loan Losses [Member] | Home equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			14,875	14,011	14,011
Charge offs			(269)		(587)
Recoveries			921		1,385
Net Charge offs			652		798
Provision for credit losses			(413)		66
Financing Receivable, Allowance for Credit Loss, Ending Balance	15,114		15,114		14,875
Allowance for credit losses on loans
Charge offs			(269)		(587)
Recoveries			921		1,385
Net Charge offs			652		798
Allowance for Loan Losses [Member] | Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			11,390	11,441	11,441
Charge offs			(3,769)		(3,363)
Recoveries			744		1,010
Net Charge offs			(3,025)		(2,353)
Provision for credit losses			3,928		2,301
Financing Receivable, Allowance for Credit Loss, Ending Balance	12,293		12,293		11,390
Allowance for credit losses on loans
Charge offs			(3,769)		(3,363)
Recoveries			744		1,010
Net Charge offs			(3,025)		(2,353)
Allowance for Loan Losses [Member] | Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Beginning Balance			84,182	68,239	68,239
Charge offs			(8,809)		(5,558)
Recoveries			2,805		3,401
Net Charge offs			(6,004)		(2,157)
Provision for credit losses			12,666		18,100
Financing Receivable, Allowance for Credit Loss, Ending Balance	90,844		90,844		84,182
Allowance for credit losses on loans
Charge offs			(8,809)		(5,558)
Recoveries			2,805		3,401
Net Charge offs			(6,004)		(2,157)
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			38,776	39,776	39,776
Provision for credit losses			(4,000)		(1,000)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	34,776		34,776		38,776
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and industrial
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			12,997	18,459	18,459
Provision for credit losses			(2,365)		(5,462)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	10,632		10,632		12,997
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — owner occupied
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			103	208	208
Provision for credit losses			15		(105)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	119		119		103
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and business lending
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			13,101	18,667	18,667
Provision for credit losses			(2,350)		(5,566)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	10,751		10,751		13,101
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — investor
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			710	936	936
Provision for credit losses			39		(226)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	749		749		710
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Real estate construction
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			20,583	15,586	15,586
Provision for credit losses			(1,000)		4,997
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	19,583		19,583		20,583
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate lending
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			21,292	16,522	16,522
Provision for credit losses			(961)		4,770
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	20,331		20,331		21,292
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total commercial
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			34,393	35,189	35,189
Provision for credit losses			(3,311)		(796)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	31,082		31,082		34,393
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Home equity
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			2,699	2,592	2,592
Provision for credit losses			(17)		107
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	2,682		2,682		2,699
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Other consumer
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			1,683	1,995	1,995
Provision for credit losses			(672)		(311)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	1,011		1,011		1,683
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total consumer
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance-Sheet, Credit Loss, Liability, Beginning Balance			4,382	4,587	4,587
Provision for credit losses			(689)		(204)
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	3,693		3,693		4,382
Allowance for Loans Losses and Unfunded Commitments [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			(40,891)		(10,146)
Recoveries			7,965		8,852
Net Charge offs			(32,925)		(1,294)
Allowance for credit losses on loans
Balance at beginning of period			351,496	319,791	319,791
Charge offs			(40,891)		(10,146)
Recoveries			7,965		8,852
Net Charge offs			(32,925)		(1,294)
Provision for credit losses			62,000		33,000
Balance at end of period	$ 380,571		$ 380,571		$ 351,496
Percent of Loans	1.26%		1.26%		1.22%
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (31,816)		$ (4,491)
Recoveries			2,322		5,282
Net Charge offs			(29,494)		791
Allowance for credit losses on loans
Balance at beginning of period			132,073	108,316	108,316
Charge offs			(31,816)		(4,491)
Recoveries			2,322		5,282
Net Charge offs			(29,494)		791
Provision for credit losses			32,345		22,967
Balance at end of period	$ 134,924		$ 134,924		$ 132,073
Percent of Loans	1.34%		1.34%		1.35%
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ 0		$ 0
Recoveries			8		13
Net Charge offs			8		13
Allowance for credit losses on loans
Balance at beginning of period			9,579	11,681	11,681
Charge offs			0		0
Recoveries			8		13
Net Charge offs			8		13
Provision for credit losses			1,991		(2,115)
Balance at end of period	$ 11,578		$ 11,578		$ 9,579
Percent of Loans	1.10%		1.10%		0.97%
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and business lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (31,816)		$ (4,491)
Recoveries			2,329		5,295
Net Charge offs			(29,487)		804
Allowance for credit losses on loans
Balance at beginning of period			141,652	119,997	119,997
Charge offs			(31,816)		(4,491)
Recoveries			2,329		5,295
Net Charge offs			(29,487)		804
Provision for credit losses			34,336		20,852
Balance at end of period	$ 146,502		$ 146,502		$ 141,652
Percent of Loans	1.31%		1.31%		1.32%
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — investor
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (242)		$ (50)
Recoveries			2,789		50
Net Charge offs			2,547		0
Allowance for credit losses on loans
Balance at beginning of period			55,108	73,739	73,739
Charge offs			(242)		(50)
Recoveries			2,789		50
Net Charge offs			2,547		0
Provision for credit losses			10,560		(18,631)
Balance at end of period	$ 68,214		$ 68,214		$ 55,108
Percent of Loans	1.31%		1.31%		1.08%
Allowance for Loans Losses and Unfunded Commitments [Member] | Real estate construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (25)		$ (48)
Recoveries			42		106
Net Charge offs			18		58
Allowance for credit losses on loans
Balance at beginning of period			66,171	53,229	53,229
Charge offs			(25)		(48)
Recoveries			42		106
Net Charge offs			18		58
Provision for credit losses			5,128		12,884
Balance at end of period	$ 71,317		$ 71,317		$ 66,171
Percent of Loans	3.35%		3.35%		3.07%
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (266)		$ (98)
Recoveries			2,831		156
Net Charge offs			2,565		58
Allowance for credit losses on loans
Balance at beginning of period			121,279	126,968	126,968
Charge offs			(266)		(98)
Recoveries			2,831		156
Net Charge offs			2,565		58
Provision for credit losses			15,687		(5,748)
Balance at end of period	$ 139,531		$ 139,531		$ 121,279
Percent of Loans	1.90%		1.90%		1.68%
Allowance for Loans Losses and Unfunded Commitments [Member] | Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (32,082)		$ (4,588)
Recoveries			5,161		5,451
Net Charge offs			(26,921)		862
Allowance for credit losses on loans
Balance at beginning of period			262,931	246,965	246,965
Charge offs			(32,082)		(4,588)
Recoveries			5,161		5,451
Net Charge offs			(26,921)		862
Provision for credit losses			50,023		15,104
Balance at end of period	$ 286,033		$ 286,033		$ 262,931
Percent of Loans	1.55%		1.55%		1.46%
Allowance for Loans Losses and Unfunded Commitments [Member] | Residential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (714)		$ (567)
Recoveries			357		908
Net Charge offs			(358)		341
Allowance for credit losses on loans
Balance at beginning of period			38,298	40,787	40,787
Charge offs			(714)		(567)
Recoveries			357		908
Net Charge offs			(358)		341
Provision for credit losses			2,496		(2,830)
Balance at end of period	$ 40,437		$ 40,437		$ 38,298
Percent of Loans	0.46%		0.46%		0.45%
Allowance for Loans Losses and Unfunded Commitments [Member] | Auto finance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (4,056)		$ (1,041)
Recoveries			783		98
Net Charge offs			(3,273)		(943)
Allowance for credit losses on loans
Balance at beginning of period			19,619	1,999	1,999
Charge offs			(4,056)		(1,041)
Recoveries			783		98
Net Charge offs			(3,273)		(943)
Provision for credit losses			6,654		18,563
Balance at end of period	$ 23,000		$ 23,000		$ 19,619
Percent of Loans	1.15%		1.15%		1.42%
Allowance for Loans Losses and Unfunded Commitments [Member] | Home equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (269)		$ (587)
Recoveries			921		1,385
Net Charge offs			652		798
Allowance for credit losses on loans
Balance at beginning of period			17,574	16,603	16,603
Charge offs			(269)		(587)
Recoveries			921		1,385
Net Charge offs			652		798
Provision for credit losses			(430)		173
Balance at end of period	$ 17,797		$ 17,797		$ 17,574
Percent of Loans	2.85%		2.85%		2.81%
Allowance for Loans Losses and Unfunded Commitments [Member] | Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (3,769)		$ (3,363)
Recoveries			744		1,010
Net Charge offs			(3,025)		(2,353)
Allowance for credit losses on loans
Balance at beginning of period			13,073	13,436	13,436
Charge offs			(3,769)		(3,363)
Recoveries			744		1,010
Net Charge offs			(3,025)		(2,353)
Provision for credit losses			3,256		1,990
Balance at end of period	$ 13,304		$ 13,304		$ 13,073
Percent of Loans	4.82%		4.82%		4.43%
Allowance for Loans Losses and Unfunded Commitments [Member] | Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge offs			$ (8,809)		$ (5,558)
Recoveries			2,805		3,401
Net Charge offs			(6,004)		(2,157)
Allowance for credit losses on loans
Balance at beginning of period			88,565	$ 72,825	72,825
Charge offs			(8,809)		(5,558)
Recoveries			2,805		3,401
Net Charge offs			(6,004)		(2,157)
Provision for credit losses			11,977		17,896
Balance at end of period	$ 94,538		$ 94,538		$ 88,565
Percent of Loans	0.81%		0.81%		0.82%