Parent Company Only Financial Information, Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flows from Operating Activities
Net income	$ 366,122	$ 350,994	$ 306,771
Adjustments to reconcile net income to net cash provided by operating activities:
Net change in other assets and other liabilities	34,072	60,025	7,666
Net cash provided by operating activities	846,566	529,551	550,020
Cash Flows from Investing Activities
Net cash (used in) investing activities	(5,254,811)	(1,584,186)	(793,737)
Cash Flows from Financing Activities
Net increase (decrease) in commercial paper	251,674	101,946	(238,655)
Redemption of Corporation's senior notes	0	300,000	0
Proceeds from issuance of common stock for stock-based compensation plans	11,061	25,702	3,966
Proceeds from issuance of preferred stock	0	0	96,796
Purchase of treasury stock, open market purchases	(938)	0	0
Cash dividends on common stock	(123,137)	(116,061)	(112,023)
Cash dividends on preferred stock	(11,500)	(17,111)	(18,358)
Other	(938)
Net cash used in financing activities	4,004,185	1,364,102	371,020
Net increase (decrease) in cash and cash equivalents	(404,060)	309,467	127,304
Treasury Stock
Cash Flows from Financing Activities
Other	(938)	0	0
Performance/Service Based RSAs, RSA, [Member]
Cash Flows from Financing Activities
Payments for Repurchase of Common Stock	(6,480)	(4,847)	(6,113)
Parent Company Only
Cash Flows from Operating Activities
Net income	366,122	350,994	306,771
Adjustments to reconcile net income to net cash provided by operating activities:
(Increase) decrease in equity in undistributed net income (loss) of subsidiaries	(343,582)	28,802	(61,406)
Net change in other assets and other liabilities	14,159	17,102	(49,890)
Net cash provided by operating activities	36,699	396,898	195,475
Cash Flows from Investing Activities
Net (increase) decrease in notes receivable from subsidiaries	115,000	20,000	(105,000)
Net cash (used in) investing activities	115,000	20,000	(105,000)
Cash Flows from Financing Activities
Net increase (decrease) in commercial paper	(13,932)	(24,616)	27,330
Proceeds from issuance of common stock for stock-based compensation plans	11,061	25,702	3,966
Proceeds from issuance of preferred stock	0	0	96,796
Redemption of preferred stock	0	(164,458)	0
Purchase of treasury stock, open market purchases	0	(132,955)	(71,255)
Cash dividends on common stock	(123,137)	(116,061)	(112,023)
Cash dividends on preferred stock	(11,500)	(17,111)	(18,358)
Net cash used in financing activities	(144,928)	(434,346)	(79,656)
Net increase (decrease) in cash and cash equivalents	6,771	(17,448)	10,819
Cash and cash equivalents at end of year	44,755	37,984	55,432
Cash and cash equivalents at beginning of year	$ 37,984	$ 55,432	$ 44,613