Income Taxes (Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Taxes computed at statutory rate, amount	$ 138,431	$ 119,292	$ (26,196)
State income taxes, net of federal income tax benefit, amount	13,272	9,048	(1,269)
Tax-exempt interest, amount	(8,612)	(9,100)	(10,444)
Life insurance contracts, amount	(1,812)	(2,653)	(4,857)
Tax credits, amount	(8,039)	(7,889)	(8,072)
Employee share-based compensation, amount	(2,084)	(1,671)	1,351
FDIC assessment disallowance, amount	1,836	1,609	2,094
Net operating loss carryback under CARES act, amount	238	(4,948)	(30,167)
Other, net, amount	1,877	1,153	(2,011)
Total expense (benefit) included in net income	$ 135,107	$ 104,841	$ (79,571)
Taxes computed at statutory rate	21.00%	21.00%	21.00%	35.00%
State income taxes, net of federal income tax benefit	2.00%	1.60%	1.00%
Tax-exempt interest	(1.30%)	(1.60%)	8.40%
Life insurance contracts	(0.30%)	(0.50%)	3.90%
Tax credits	(1.20%)	(1.40%)	6.50%
Employee share-based compensation	(0.30%)	(0.30%)	(1.10%)
FDIC assessment disallowance	0.30%	0.30%	(1.70%)
Net operating loss carryback under CARES act		(0.90%)	24.20%
Other, net	0.30%	0.30%	1.60%
Income tax expense	20.50%	18.50%	63.80%