Derivative Financial Instruments (Schedule fair value of derivative instruments) (Detail) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	$ 7,740,659,000	$ 5,554,015,000
Asset Derivatives, Fair Value, before netting	219,493,000	159,117,000
Asset Derivatives, Fair Value, Less: Master netting agreements	16,877,000	6,364,000
Asset Derivatives, Fair Value, Less: Cash collateral posted	185,968,000	19,272,000
Total derivative instruments, after netting	16,648,000	133,481,000
Liability Derivatives, Notional Amount	9,207,567,000	4,747,534,000
Liability Derivatives, Fair Value	426,777,000	21,784,000
Liability Derivatives, Fair Value, Less: Master netting agreements	16,877,000	6,364,000
Liability Derivatives, Fair Value, Less: Cash collateral posted	0	2,119,000
Total derivative instruments, after netting	409,900,000	13,301,000
CME
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Less: Cash collateral posted	64,800,000
Total derivative instruments, after netting	0
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	219,245,000	25,636,000
Asset Derivatives, Fair Value, Less: Master netting agreements	16,877,000	6,364,000
Total derivative instruments, after netting	185,968,000	19,272,000
Liability Derivatives, Fair Value	16,877,000	8,483,000
Liability Derivatives, Fair Value, Less: Master netting agreements	16,877,000	6,364,000
Total derivative instruments, after netting	0	2,119,000
Designated as Hedging Instrument | Interest rate derivatives
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	850,000,000	1,000,000,000
Asset Derivatives, Fair Value	243,000	17,583,000
Liability Derivatives, Notional Amount	2,000,000,000	0
Liability Derivatives, Fair Value	16,377,000	0
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	6,890,659,000	4,554,015,000
Asset Derivatives, Fair Value, Total	219,250,000	141,534,000
Liability Derivatives, Notional Amount	7,207,567,000	4,747,534,000
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	410,400,000	21,784,000
Not Designated as Hedging Instrument | Interest rate derivatives
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	6,731,008,000	4,463,048,000
Asset Derivatives, Fair Value	217,613,000	141,243,000
Liability Derivatives, Notional Amount	6,721,716,000	4,372,846,000
Liability Derivatives, Fair Value	409,950,000	21,570,000
Not Designated as Hedging Instrument | Mortgage Banking Derivatives | RPA-Out
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	4,445,000	14,212,000
Asset Derivatives, Fair Value	36,000	80,000
Not Designated as Hedging Instrument | Mortgage Banking Derivatives | RPA-In
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	476,000	0
Liability Derivatives, Fair Value	3,000	0
Not Designated as Hedging Instrument | Other
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	155,206,000	76,755,000
Asset Derivatives, Fair Value	1,601,000	211,000
Liability Derivatives, Notional Amount	485,375,000	374,688,000
Liability Derivatives, Fair Value	447,000	214,000
Not Designated as Hedging Instrument | Interest Rate Swap, CME
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	2,900,000,000	400,000,000
Liability Derivatives, Notional Amount	0	2,600,000,000
Not Designated as Hedging Instrument | Credit Risk Contract | RPA-Out
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	103,700,000	66,000,000
Not Designated as Hedging Instrument | Credit Risk Contract | RPA-In
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	464,700,000	338,200,000
Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Other commitment	$ 2,800,000	$ 1,000,000