Derivative Instruments and Hedging Activities - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) swap	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) swap	Sep. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Notional amount	$ 19,075,382		$ 19,075,382			$ 18,678,243
Loans	49,355,319		49,355,319			50,210,295
Consumer loans
Derivative [Line Items]
Loans	3,469,757		3,469,757			3,440,695
Consumer loans | Automobile
Derivative [Line Items]
Loans	1,823,738		1,823,738			1,620,389
Derivatives not designated as hedging instruments:
Derivative [Line Items]
Notional amount	18,295,060		18,295,060			17,878,243
Interest rate swaps
Derivative [Line Items]
Accumulated net after-tax gains related to effective cash flow hedges	1,500		1,500			2,100
Interest rate swaps | Interest income
Derivative [Line Items]
Amounts reclassified to income statement	1,200		1,200
Interest rate swaps | Fair value hedge interest rate swaps | Interest income
Derivative [Line Items]
Fee income related to derivative interest rate swaps executed with commercial loan customers	(2,385)	$ 0	3,170	$ 0
Interest rate swaps | Fair value hedge interest rate swaps | Noninterest Income
Derivative [Line Items]
Fee income related to derivative interest rate swaps executed with commercial loan customers	5,700	$ 5,700	17,000	$ 29,700
Interest rate swaps | Derivatives designated as hedging instruments
Derivative [Line Items]
Derivative, notional amount, terminated	500,000		500,000
Notional amount	$ 480,300		$ 480,300
Number of instruments held | swap	11		11
Interest rate swaps | Derivatives designated as hedging instruments | Minimum
Derivative [Line Items]
Fixed interest rate	4.12%		4.12%
Interest rate swaps | Derivatives designated as hedging instruments | Maximum
Derivative [Line Items]
Fixed interest rate	4.65%		4.65%
Interest rate swaps | Derivatives designated as hedging instruments | Fair value hedge interest rate swaps
Derivative [Line Items]
Notional amount	$ 780,322		$ 780,322			800,000
Interest rate swaps | Derivatives not designated as hedging instruments:
Derivative [Line Items]
Notional amount	$ 15,515,102		$ 15,515,102			16,282,279
Number of instruments held | swap	47		47
Interest rate swaps | Derivatives not designated as hedging instruments: | Fair value hedge interest rate swaps
Derivative [Line Items]
Notional amount	$ 10,400		$ 10,400
Number of instruments held | swap	2		2
Interest rate swaps | Derivatives not designated as hedging instruments: | Risk Participation Agreement
Derivative [Line Items]
Notional amount	$ 596,300		$ 596,300
Credit default swap | Derivatives not designated as hedging instruments:
Derivative [Line Items]
Notional amount	1,287,149		1,287,149		$ 1,500,000	$ 0
Derivative, cost of hedge	$ 3,200		$ 4,700