Commitments and Contingencies - Amounts Related to Fair Value of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2021
Hedged item—subordinated debt and loans:
Derivative [Line Items]
Other Assets	$ 0	$ 0
Other Liabilities	479,345	594,476
Derivative—interest rate swaps:
Derivative [Line Items]
Notional Amount	500,000		$ 300,000
Derivatives designated as hedging instruments:
Derivative [Line Items]
Notional Amount	800,000	900,000
Derivatives not designated as hedging instruments:
Derivative [Line Items]
Notional Amount	17,878,243	16,058,364
Derivatives not designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Notional Amount	16,282,279	14,753,330
Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Notional Amount	1,557,167	1,273,735
Derivatives not designated as hedging instruments: | Mortgage banking derivatives
Derivative [Line Items]
Notional Amount	38,797	31,299
Other Assets | Derivatives designated as hedging instruments:
Derivative [Line Items]
Other Assets	0	3,971
Other Assets | Derivatives not designated as hedging instruments:
Derivative [Line Items]
Other Assets	466,227	463,156
Other Assets | Derivatives not designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Other Assets	458,129	449,280
Other Assets | Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Other Assets	8,024	13,709
Other Assets | Derivatives not designated as hedging instruments: | Mortgage banking derivatives
Derivative [Line Items]
Other Assets	74	167
Other Liabilities | Derivatives designated as hedging instruments:
Derivative [Line Items]
Other Liabilities	21,460	29,798
Other Liabilities | Derivatives not designated as hedging instruments:
Derivative [Line Items]
Other Liabilities	466,643	577,439
Other Liabilities | Derivatives not designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Other Liabilities	457,885	564,678
Other Liabilities | Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Other Liabilities	8,286	12,604
Other Liabilities | Derivatives not designated as hedging instruments: | Mortgage banking derivatives
Derivative [Line Items]
Other Liabilities	472	157
Cash flow hedge interest rate swaps | Derivatives designated as hedging instruments: | Hedged item—subordinated debt and loans:
Derivative [Line Items]
Notional Amount	0	600,000
Cash flow hedge interest rate swaps | Derivatives designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Notional Amount	600,000
Cash flow hedge interest rate swaps | Other Assets | Derivatives designated as hedging instruments: | Hedged item—subordinated debt and loans:
Derivative [Line Items]
Other Assets	0	3,971
Cash flow hedge interest rate swaps | Other Liabilities | Derivatives designated as hedging instruments: | Hedged item—subordinated debt and loans:
Derivative [Line Items]
Other Liabilities	0	4
Fair value hedge interest rate swaps | Derivatives designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Notional Amount	800,000	300,000
Fair value hedge interest rate swaps | Derivatives not designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Notional Amount	10,400
Fair value hedge interest rate swaps | Other Assets | Derivatives designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Other Assets	0	0
Fair value hedge interest rate swaps | Other Liabilities | Derivatives designated as hedging instruments: | Derivative—interest rate swaps:
Derivative [Line Items]
Other Liabilities	$ 21,460	$ 29,794