Shareholders' Equity and Other Comprehensive Income (Loss) (Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Beginning balance	$ 4,475,801	$ 5,296,800
Total other comprehensive income (loss), net of tax	152,790	(579,744)
Ending balance	4,770,130	4,824,635
Accumulated other comprehensive loss	1,289,327		$ 1,442,117
Total
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Beginning balance	(1,442,117)	(82,321)
Other comprehensive income (loss) before reclassifications	123,387	(578,076)
Amounts reclassified from AOCI	29,403	(1,668)
Total other comprehensive income (loss), net of tax	152,790	(579,744)
Ending balance	(1,289,327)	(662,065)
Net unrealized gains (losses) on investment securities available for sale
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Beginning balance	(1,220,263)	(67,980)
Other comprehensive income (loss) before reclassifications	115,821	(474,459)
Amounts reclassified from AOCI	(779)	0
Total other comprehensive income (loss), net of tax	115,042	(474,459)
Ending balance	(1,105,221)	(542,439)
Accumulated other comprehensive loss	13,300
Net unrealized gains (losses) on cash flow hedges
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Beginning balance	(221,854)	(14,341)
Other comprehensive income (loss) before reclassifications	7,566	(103,617)
Amounts reclassified from AOCI	30,182	(1,668)
Total other comprehensive income (loss), net of tax	37,748	(105,285)
Ending balance	(184,106)	$ (119,626)
Accumulated other comprehensive loss	$ 12,100