Borrowings - Schedule of Short-Term and Long-Term Borrowings (Details) - USD ($) $ in Thousands	1 Months Ended
	Jan. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Aug. 05, 2014
Long-Term Borrowings
Debt instrument, unused borrowing capacity, amount		$ 2,490,213	$ 752,509
Total borrowings, gross		1,400,587	1,080,101
Unamortized deferred issuance costs		(82)	(206)
Net Borrowings Outstanding		1,400,505	$ 1,079,895
Line of credit facility, maximum borrowing capacity		2,200,000
Investment securities pledged with collateral par		292,300
Asset Pledged as Collateral
Long-Term Borrowings
Debt instrument, unused borrowing capacity, amount		$ 1,900,000
Subordinated Debt
Long-Term Borrowings
Interest rate (as a percent)		5.75%	5.75%	5.75%
Long-term borrowings, gross		$ 70,000	$ 70,000
Unamortized deferred issuance costs		(82)	(206)
Subordinated notes, net		69,918	69,794
Face amount		69,900	69,800	$ 70,000
Customer repurchase agreements
Long-Term Borrowings
Total short-term borrowings		$ 30,587	$ 35,100
Interest rate (as a percent)		3.42%	2.94%
FHLB secured borrowings | Secured Debt
Long-Term Borrowings
Total short-term borrowings		$ 0	$ 975,001
Debt instrument, unused borrowing capacity, amount		1,271,846	$ 145,104
Interest rate (as a percent)			4.57%
BTFP secured borrowings | Asset Pledged as Collateral
Long-Term Borrowings
Debt instrument, unused borrowing capacity, amount		598,900
BTFP secured borrowings | Secured Debt
Long-Term Borrowings
Total short-term borrowings		1,300,000
Debt instrument, unused borrowing capacity, amount		$ 598,870
Interest rate (as a percent)		4.53%
BTFP secured borrowings | Secured Debt | Subsequent Event
Long-Term Borrowings
Interest rate (as a percent)	4.76%
Securities borrowed	$ 500,000
Short-term debt, refinanced, amount	500,000
Face amount	$ 800,000
Discount window secured borrowings | Secured Debt
Long-Term Borrowings
Debt instrument, unused borrowing capacity, amount		$ 601,504	$ 607,405
Raymond James repurchase agreement | Asset Pledged as Collateral
Long-Term Borrowings
Debt instrument, unused borrowing capacity, amount		18,000
Raymond James repurchase agreement | Secured Debt
Long-Term Borrowings
Debt instrument, unused borrowing capacity, amount		$ 17,993