Allowance for Credit Losses (Allowance for Credit Losses Methodology) (Details) - USD ($) $ in Thousands		3 Months Ended
	Feb. 28, 2023	Mar. 31, 2024	Mar. 31, 2023
Allowance for credit losses on loans and leases
Balance, beginning of period		$ 440,871	$ 301,135
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	17,476	106,498
Charge-offs		(49,753)	(20,269)
Recoveries		5,750	3,608
Net recoveries (charge-offs)		(44,003)	(16,661)
Balance, end of period		414,344	417,464
Reserve for unfunded commitments
Balance, beginning of period		23,208	14,221
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period			5,767
(Recapture) provision for credit losses on unfunded commitments		(340)	(959)
Balance, end of period		22,868	19,029
Total allowance for credit losses		437,212	436,493
Commercial real estate
Allowance for credit losses on loans and leases
Balance, beginning of period		125,888	77,813
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date			8,736
(Recapture) provision for credit losses for loans and leases		20,191	24,483
Charge-offs		(161)	0
Recoveries		358	58
Net recoveries (charge-offs)		197	58
Balance, end of period		146,276	111,090
Reserve for unfunded commitments
Balance, beginning of period		11,170	7,207
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period			2,257
(Recapture) provision for credit losses on unfunded commitments		1,858	(1,059)
Balance, end of period		13,028	8,405
Total allowance for credit losses		159,304	119,495
Commercial
Allowance for credit losses on loans and leases
Balance, beginning of period		244,821	167,135
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date			17,204
(Recapture) provision for credit losses for loans and leases		436	70,997
Charge-offs		(47,232)	(19,248)
Recoveries		4,732	3,058
Net recoveries (charge-offs)		(42,500)	(16,190)
Balance, end of period		202,757	239,146
Reserve for unfunded commitments
Balance, beginning of period		7,841	3,049
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period			3,066
(Recapture) provision for credit losses on unfunded commitments		(1,951)	266
Balance, end of period		5,890	6,381
Total allowance for credit losses		208,647	245,527
Residential
Allowance for credit losses on loans and leases
Balance, beginning of period		62,004	50,329
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date			454
(Recapture) provision for credit losses for loans and leases		(3,674)	9,955
Charge-offs		(490)	(248)
Recoveries		170	123
Net recoveries (charge-offs)		(320)	(125)
Balance, end of period		58,010	60,613
Reserve for unfunded commitments
Balance, beginning of period		2,940	3,196
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period			268
(Recapture) provision for credit losses on unfunded commitments		(183)	(144)
Balance, end of period		2,757	3,320
Total allowance for credit losses		60,767	63,933
Consumer Portfolio Segment [Member]
Allowance for credit losses on loans and leases
Balance, beginning of period		8,158	5,858
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date			98
(Recapture) provision for credit losses for loans and leases		523	1,063
Charge-offs		(1,870)	(773)
Recoveries		490	369
Net recoveries (charge-offs)		(1,380)	(404)
Balance, end of period		7,301	6,615
Reserve for unfunded commitments
Balance, beginning of period		1,257	769
Off-Balance-Sheet, Credit Loss, Liability, acquired during the period			176
(Recapture) provision for credit losses on unfunded commitments		(64)	(22)
Balance, end of period		1,193	923
Total allowance for credit losses		$ 8,494	$ 7,538