Parent Company Only Financial Statements Parent Company Only Financial Statements, Condensed Cash Flow Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities: [Abstract]
Net income	$ 616,325	$ 435,071	$ 500,685
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Other gains, net	67,446	15,949	583
Change in other assets	(12,568)	1,739	18,955
Change in other liabilities	12,897	8,895	92,463
Net cash provided by operating activities	(3,692,577)	(416,256)	(473,679)
Cash Flows From Investing Activities: [Abstract]
Net cash used in investing activities	2,602,672	(2,458,835)	(2,323,737)
Cash Flows From Financing Activities: [Abstract]
Repayment of subordinated debentures	150,000	0	0
Issuance of common and treasury stock, net	(4,874)	(4,933)	(7)
Dividends paid	(144,105)	(144,437)	(143,496)
Repurchase of common stock	(117,938)	(75,830)	(129,483)
Net cash used in financing activities	2,746,742	2,796,843	2,912,813
Net increase (decrease) in cash and cash equivalents	1,656,837	(78,248)	115,397
Cash and cash equivalents at beginning of period	1,180,573	1,258,821	1,143,424
Cash and cash equivalents at end of period	2,837,410	1,180,573	1,258,821
Cash paid for interest	68,775	160,288	417,070
Parent Company [Member]
Cash Flows From Operating Activities: [Abstract]
Net income	618,121	435,030	500,758
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Equity in undistributed income of bank subsidiaries	(126,380)	(276,217)	(166,797)
Equity in undistributed income of non-bank subsidiaries	(11,738)	35,610	10,768
Other gains, net	3,415	(1,465)	(3,310)
Change in other assets	(1,160)	(15,225)	1,765
Change in other liabilities	389	850	855
Net cash provided by operating activities	484,967	209,033	340,509
Cash Flows From Investing Activities: [Abstract]
Investment in subsidiaries	(25,665)	(14,807)	(19,837)
Dissolution of subsidiaries	4,457	0	0
Net cash used in investing activities	(21,208)	(14,807)	(19,837)
Cash Flows From Financing Activities: [Abstract]
Repayment of subordinated debentures	(150,000)	0	0
Issuance of common and treasury stock, net	(4,874)	(4,933)	(7)
Dividends paid	(144,105)	(144,437)	(143,496)
Repurchase of common stock	(117,938)	(75,830)	(129,483)
Net cash used in financing activities	(416,917)	(225,200)	(272,986)
Net increase (decrease) in cash and cash equivalents	46,842	(30,974)	47,686
Cash and cash equivalents at beginning of period	183,805	214,779	167,093
Cash and cash equivalents at end of period	230,647	183,805	214,779
Cash paid for interest	$ 10,559	$ 14,064	$ 15,099