Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred income tax assets
Net unrealized losses on investment securities available for sale and cash flow hedges	$ 455,744	$ 19,261
Allowance for credit losses	121,941	112,180
Lease liability	107,818	102,412
Employee benefits and deferred compensation	42,746	36,701
Net operating loss carryforwards	23,590	23,897
Tax credit carryforwards	14,553	15,870
Unrealized losses on fair value hedges	11,101	0
Miscellaneous accrued expenses	5,125	3,870
Fair value of investment securities and loans	2,019	6,439
Non-performing loan interest	2,695	2,621
Deferred revenue	0	14,616
Other	6,585	6,182
Total gross deferred tax assets	793,917	344,049
Less valuation allowance	(19,114)	(19,003)
Total deferred tax assets	774,803	325,046
Deferred tax liabilities
Right-of-use asset	(102,945)	(98,773)
Excess tax over financial statement depreciation	(23,762)	(27,355)
Purchase accounting intangibles	(15,224)	(14,820)
Deferred loan fees	(15,901)	0
Unrealized gain on hedged liabilities	(11,101)	0
Prepaid expense	(4,947)	(4,631)
Other properties held for sale	(2,828)	(5,345)
Other	(2,778)	(5,071)
Total gross deferred tax liabilities	(179,486)	(155,995)
Net deferred tax assets	$ 595,317	$ 169,051