Derivative Instruments and Hedging Activities - Additional Information (Details)				3 Months Ended		6 Months Ended
	Jun. 28, 2021	May 28, 2021	May 25, 2021	Jun. 30, 2021 USD ($) swap	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) swap	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Derivative [Line Items]
Subordinated borrowing interest rate		3.00%	3.00%
Aggregate fair value of net liability position				$ 79,600,000		$ 79,600,000
Derivatives not designated as hedging instruments:
Derivative [Line Items]
Notional amount				10,292,758,000		10,292,758,000		$ 9,211,043,000
Interest rate swaps
Derivative [Line Items]
Notional amount				300,000,000		300,000,000
Accumulated net after-tax losses related to effective cash flow hedges				2,700,000		2,700,000		4,000,000.0
Reclassified to interest expense				2,300,000		2,300,000
Interest rate swaps | Fair value hedge | Noninterest Income
Derivative [Line Items]
Fee income related to derivative interest rate swaps executed with commercial loan customers				7,600,000	$ 14,700,000	13,800,000	$ 28,900,000
Interest rate swaps | Derivatives not designated as hedging instruments:
Derivative [Line Items]
Notional amount				$ 9,962,230,000		$ 9,962,230,000		$ 8,889,557,000
Number of instruments held | swap				26		26
Interest rate swaps | Derivatives not designated as hedging instruments: | Fair value hedge
Derivative [Line Items]
Notional amount				$ 10,400,000		$ 10,400,000
Number of instruments held | swap				2		2
Interest rate swaps | Derivatives not designated as hedging instruments: | Risk Participation Agreement
Derivative [Line Items]
Notional amount				$ 215,800,000		$ 215,800,000
Interest rate swaps | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Derivative [Line Items]
Subordinated debt basis points	2.187%