Allowance for Credit Losses (Allowance for Credit Losses Methodology) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Feb. 28, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Allowance for credit losses on loans and leases
Balance, beginning of period		$ 417,464	$ 248,564	$ 301,135	$ 248,412
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				26,492
(Recapture) provision for credit losses for loans and leases	$ 88,400	15,216	18,787	121,714	24,483
Charge-offs		(33,478)	(9,879)	(53,747)	(18,789)
Recoveries		5,401	3,639	9,009	7,005
Net recoveries (charge-offs)		(28,077)	(6,240)	(44,738)	(11,784)
Balance, end of period		404,603	261,111	404,603	261,111
Reserve for unfunded commitments
Balance, beginning of period		19,029	12,918	14,221	12,767
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period				5,767
(Recapture) provision for credit losses on unfunded commitments		798	(95)	(161)	56
Balance, end of period		19,827	12,823	19,827	12,823
Total allowance for credit losses		424,430	273,934	424,430	273,934
Commercial real estate
Allowance for credit losses on loans and leases
Balance, beginning of period		111,090	91,638	77,813	99,075
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				8,736
(Recapture) provision for credit losses for loans and leases		7,829	(2,720)	32,312	(10,182)
Charge-offs		(174)	(8)	(174)	(8)
Recoveries		209	73	267	98
Net recoveries (charge-offs)		35	65	93	90
Balance, end of period		118,954	88,983	118,954	88,983
Reserve for unfunded commitments
Balance, beginning of period		8,405	8,738	7,207	8,461
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period				2,257
(Recapture) provision for credit losses on unfunded commitments		1,595	(1,387)	536	(1,110)
Balance, end of period		10,000	7,351	10,000	7,351
Total allowance for credit losses		128,954	96,334	128,954	96,334
Commercial
Allowance for credit losses on loans and leases
Balance, beginning of period		239,146	121,072	167,135	117,573
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				17,204
(Recapture) provision for credit losses for loans and leases		30	16,484	71,027	25,296
Charge-offs		(32,036)	(9,035)	(51,284)	(16,893)
Recoveries		4,511	2,934	7,569	5,479
Net recoveries (charge-offs)		(27,525)	(6,101)	(43,715)	(11,414)
Balance, end of period		211,651	131,455	211,651	131,455
Reserve for unfunded commitments
Balance, beginning of period		6,381	1,620	3,049	2,028
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period				3,066
(Recapture) provision for credit losses on unfunded commitments		(560)	612	(294)	204
Balance, end of period		5,821	2,232	5,821	2,232
Total allowance for credit losses		217,472	133,687	217,472	133,687
Residential
Allowance for credit losses on loans and leases
Balance, beginning of period		60,613	31,946	50,329	29,068
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				454
(Recapture) provision for credit losses for loans and leases		5,269	4,424	15,224	7,296
Charge-offs		(4)	0	(252)	(167)
Recoveries		63	216	186	389
Net recoveries (charge-offs)		59	216	(66)	222
Balance, end of period		65,941	36,586	65,941	36,586
Reserve for unfunded commitments
Balance, beginning of period		3,320	2,193	3,196	1,957
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period				268
(Recapture) provision for credit losses on unfunded commitments		(302)	542	(446)	778
Balance, end of period		3,018	2,735	3,018	2,735
Total allowance for credit losses		68,959	39,321	68,959	39,321
Consumer Portfolio Segment [Member]
Allowance for credit losses on loans and leases
Balance, beginning of period		6,615	3,908	5,858	2,696
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				98
(Recapture) provision for credit losses for loans and leases		2,088	599	3,151	2,073
Charge-offs		(1,264)	(836)	(2,037)	(1,721)
Recoveries		618	416	987	1,039
Net recoveries (charge-offs)		(646)	(420)	(1,050)	(682)
Balance, end of period		8,057	4,087	8,057	4,087
Reserve for unfunded commitments
Balance, beginning of period		923	367	769	321
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period				176
(Recapture) provision for credit losses on unfunded commitments		65	138	43	184
Balance, end of period		988	505	988	505
Total allowance for credit losses		$ 9,045	$ 4,592	$ 9,045	$ 4,592