Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income, Before-tax Amount	$ 356,002	$ 347,763	$ 209,445
Net income, Tax (Expense) Benefit	(78,530)	(77,962)	(45,356)
Net income, Net of Tax Amount	277,472	269,801	164,089
Unrealized gains (losses) on available-for-sale securities:
Unrealized holding (losses) gains, Before-tax Amount	(428,605)	(92,231)	39,385
Unrealized holding (losses) gains, Tax (Expense) Benefit	101,344	23,294	(9,514)
Unrealized holding (losses) gains, Net of Tax Amount	(327,261)	(68,937)	29,871
Reclassification of securities from available-for-sale to held-to-maturity, Before-tax Amount	87,444	0	0
Reclassification of securities from available-for-sale to held-to-maturity, Tax (Expense) Benefit	(20,770)	0	0
Reclassification of securities from available-for-sale to held-to-maturity, Net of Tax Amount	66,674	0	0
Realized (gains) losses included in net income, Before-tax Amount	3,872	(83)	(748)
Realized (gains) losses included in net income, Tax (Expense) Benefit	(1,026)	(46)	191
Realized (gains) losses included in net income, Net of Tax Amount	2,846	(129)	(557)
Net unrealized (losses) gains, Before-tax Amount	(337,289)	(92,314)	38,637
Net unrealized (losses) gains, Tax (Expense) Benefit	79,548	23,248	(9,323)
Net unrealized (losses) gains, Net of Tax Amount	(257,741)	(69,066)	29,314
Unrealized losses on held-to-maturity securities transferred from available-for-sale:
Reclassification of unrealized losses, Before-tax Amount	(87,444)	0	0
Reclassification of unrealized losses, Tax (Expense) Benefit	20,770	0	0
Reclassification of unrealized losses, Net of Tax Amount	(66,674)	0	0
Amortization of unrealized losses, Before-tax amount	9,049	0	723
Amortization of unrealized losses, Tax (Expense) Benefit	(2,167)	0	(173)
Amortization of unrealized losses, , Net of Tax Amount	6,882	0	550
Net activity, Before-tax Amount	(78,395)	0	723
Net activity, Tax (Expense) Benefit	18,603	0	(173)
Net activity, Net of Tax Amount	(59,792)	0	550
Derivative instruments designated as cash flow hedges:
Unrealized holding gains (losses) on derivatives, Before-tax Amount	12,721	3,837	(149)
Unrealized holding gains (losses) on derivatives, Tax (Expense) Benefit	(3,249)	(979)	38
Unrealized holding gains (losses) on derivatives, Net of Tax Amount	9,472	2,858	(111)
Losses on derivative instruments realized in net income, Before-tax Amount	269	608	359
Losses on derivative instruments realized in net income, Tax (Expense) Benefit	(69)	(156)	(91)
Losses on derivative instruments realized in net income, Net of Tax Amount	200	452	268
Net cash flow hedge activity, Before-tax Amount	12,990	4,445	210
Net cash flow hedge activity, Tax (Expense) Benefit	(3,318)	(1,135)	(53)
Net cash flow hedge activity, Net of Tax Amount	9,672	3,310	157
Defined benefit pension plan activity:
Net actuarial gain (loss) on defined benefit pension plans, Before-tax Amount	5,833	1,066	(1,804)
Net actuarial gain (loss) on defined benefit pension plans, Tax (Expense) Benefit	(1,490)	(273)	461
Net actuarial gain (loss) on defined benefit pension plans, Net of Tax Amount	4,343	793	(1,343)
Amortization of defined benefit pension plan net periodic pension cost components, Before-tax Amount	680	1,044	857
Amortization of defined benefit pension plan net periodic pension cost components, Tax (Expense) Benefit	(174)	(267)	(219)
Amortization of defined benefit pension plan net periodic pension cost components, Net of Tax Amount	506	777	638
Net defined benefit pension plan activity, Before-tax Amount	6,513	2,110	(947)
Net defined benefit pension plan activity, Tax (Expense) Benefit	(1,664)	(540)	242
Net defined benefit pension plan activity, Net of Tax Amount	4,849	1,570	(705)
Total other comprehensive (loss) income, Before-tax Amount	(396,181)	(85,759)	38,623
Total other comprehensive (loss) income, Tax (Expense) Benefit	93,169	21,573	(9,307)
Total other comprehensive (loss) income, Net of Tax Amount	(303,012)	(64,186)	29,316
Comprehensive (loss) income, Before-tax Amount	(40,179)	262,004	248,068
Comprehensive (loss) income, Tax (Expense) Benefit	14,639	(56,389)	(54,663)
Comprehensive (loss) income, Net of Tax Amount	$ (25,540)	$ 205,615	$ 193,405