Derivatives (Fair Values of Derivative Financial Instruments) (Details) - USD ($)		3 Months Ended	12 Months Ended
		Mar. 31, 2025	Dec. 31, 2024
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		$ 7,273,317,000	$ 7,392,532,000
Fair Values, Assets		$ 57,271,000	$ 71,893,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets	Other Assets
Fair Values, Assets	[1]	$ 126,178,000	$ 150,253,000
Less: netting adjustment	[1]	(60,402,000)	(76,413,000)	[2]
Total derivative assets/liabilities	[1]	65,776,000	73,840,000
Fair Values, Liabilities		46,865,000	54,707,000
Fair Values, Liabilities	[1]	129,929,000	160,623,000
Less: netting adjustment	[1]	(0)
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Total derivative assets/liabilities	[1]	129,929,000	160,623,000
Derivatives Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		1,977,500,000	1,827,500,000
Fair Values, Assets	[1]	33,187,000	39,647,000
Fair Values, Liabilities	[1]	34,883,000	48,022,000
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		5,295,817,000	5,565,032,000
Fair Values, Assets	[1]	92,991,000	110,606,000
Fair Values, Liabilities	[1]	95,046,000	112,601,000
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		4,639,533,000	4,926,461,000
Fair Values, Assets	[1]	90,206,000	108,702,000
Fair Values, Liabilities	[1]	90,316,000	108,761,000
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		378,068,000	445,554,000
Fair Values, Assets	[1]	8,000	7,000
Fair Values, Liabilities	[1]	116,000	9,000
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		41,443,000	25,526,000
Fair Values, Assets	[1]	902,000
Fair Values, Liabilities	[1]		383,000
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		25,373,000	27,465,000
Fair Values, Assets	[1]		420,000
Fair Values, Liabilities	[1]	594,000	0
Derivatives Not Designated as Hedging Instruments [Member] | To Be Announced (TBA) Securities [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		28,500,000	15,250,000
Fair Values, Assets	[1]	7,000	88,000
Fair Values, Liabilities	[1]	71,000	1,000
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		140,998,000	82,756,000
Fair Values, Assets	[1]	1,868,000	1,389,000
Fair Values, Liabilities	[1]	1,806,000	1,358,000
Derivatives Not Designated as Hedging Instruments [Member] | Visa Class B derivative contract [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		41,902,000	42,020,000
Fair Values, Liabilities	[1]	2,143,000	2,089,000
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Variable Rate Loans [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		1,500,000,000	1,350,000,000
Fair Values, Assets	[1]	1,371,000
Fair Values, Liabilities	[1]	$ 34,883,000	$ 48,022,000
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Variable Rate Loans [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets	Other Assets
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Other Liabilities	Other Liabilities
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Securities [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		$ 477,500,000	$ 477,500,000
Fair Values, Assets	[1]	$ 31,816,000	$ 39,647,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets	Other Assets
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Other Liabilities	Other Liabilities

[1] Derivative assets and liabilities are reported in other assets and other liabilities, respectively, in the consolidated balance sheets.

[2] Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information.