v3.22.4
Fair Value Measurements (Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis) (Detail) - USD ($)
$ in Thousands
Dec. 31, 2022
Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value $ 18,243,605 $ 13,924,628
Trading account securities 28,045 25,162
Derivative assets: 118,994 23,339
Derivative liabilities: 73,829 114,019
Interest Rate Swaps Caps And Floors [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets: 86,793 44,310
Derivative liabilities: 95,533 25,261
Commodity Swaps And Options [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets: 106,685 114,757
Derivative liabilities: 105,392 113,261
Foreign Exchange Forward [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets: 11 33
Derivative liabilities: 11 55
US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 5,051,587 2,179,433
Trading account securities 25,879 24,237
Residential Mortgage Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 6,376,236 4,066,265
US States and Political Subdivisions Debt Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 6,773,355 7,636,571
Trading account securities 2,166 925
Other Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 42,427 42,359
Level 1 [Member] | Foreign Exchange Forward [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets: 11 33
Derivative liabilities: 11 55
Level 1 [Member] | US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 5,051,587 2,179,433
Trading account securities 25,879 24,237
Level 2 [Member] | Interest Rate Swaps Caps And Floors [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets: 86,793 44,310
Derivative liabilities: 95,533 25,261
Level 2 [Member] | Commodity Swaps And Options [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets: 106,685 114,757
Derivative liabilities: 105,392 113,261
Level 2 [Member] | Residential Mortgage Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 6,376,236 4,066,265
Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 6,773,355 7,636,571
Trading account securities 2,166 925
Level 2 [Member] | Other Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 42,427 42,359
US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 5,051,587 2,179,433
Trading account securities 25,879 24,237
Residential Mortgage Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 6,376,236 4,066,265
US States and Political Subdivisions Debt Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value 6,773,355 7,636,571
Trading account securities 2,166 925
Other Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale, at estimated fair value $ 42,427 $ 42,359