Derivatives (Fair Values of Derivative Financial Instruments) (Details) - USD ($)		9 Months Ended	12 Months Ended
		Sep. 30, 2024	Dec. 31, 2023
Derivatives Fair Value [Line Items]
Notional or contractual amount		$ 7,448,608,000	$ 7,691,719,000
Fair Values, Assets		$ 55,440,000	$ 84,458,000
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets	Other Assets
Fair Values, Assets	[1]	$ 118,824,000	$ 156,360,000
Less: netting adjustment	[1]	(49,009,000)	(65,648,000)	[2]
Total derivative assets/liabilities	[1]	69,815,000	90,712,000
Fair Values, Liabilities		52,690,000	87,567,000
Fair Values, Liabilities	[1]	132,038,000	207,138,000
Less: netting adjustment	[1]	(9,000)
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Total derivative assets/liabilities	[1]	132,029,000	207,138,000
Derivatives Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		1,827,500,000	2,027,500,000
Fair Values, Assets	[1]	22,071,000	22,819,000
Fair Values, Liabilities	[1]	33,120,000	73,611,000
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		5,621,108,000	5,664,219,000
Fair Values, Assets	[1]	96,753,000	133,541,000
Fair Values, Liabilities	[1]	98,918,000	133,527,000
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		4,989,753,000	5,128,144,000
Fair Values, Assets	[1]	94,228,000	131,271,000
Fair Values, Liabilities	[1]	94,490,000	129,994,000
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		389,443,000	364,906,000
Fair Values, Assets	[1]	19,000	34,000
Fair Values, Liabilities	[1]	19,000	18,000
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		39,343,000	13,355,000
Fair Values, Assets	[1]	714,000
Fair Values, Liabilities	[1]		286,000
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		23,698,000	18,563,000
Fair Values, Assets	[1]		372,000
Fair Values, Liabilities	[1]	440,000	0
Derivatives Not Designated as Hedging Instruments [Member] | To Be Announced (TBA) Securities [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		29,500,000	13,500,000
Fair Values, Assets	[1]	88,000
Fair Values, Liabilities	[1]	44,000	47,000
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		106,754,000	83,134,000
Fair Values, Assets	[1]	1,704,000	1,864,000
Fair Values, Liabilities	[1]	1,664,000	1,840,000
Derivatives Not Designated as Hedging Instruments [Member] | Visa Class B derivative contract [Member]
Derivatives Fair Value [Line Items]
Notional or contractual amount		42,617,000	42,617,000
Fair Values, Liabilities	[1]	2,261,000	1,342,000
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		1,350,000,000	1,550,000,000
Fair Values, Liabilities	[1]	$ 33,120,000	$ 73,611,000
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]	$ 22,071,000	$ 22,819,000
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.