Shareholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions			3 Months Ended		6 Months Ended
	Aug. 20, 2021	Jul. 22, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Number of shares authorized to be repurchased			6.1		6.1
Purchase of treasury stock			$ 86.8	$ 30.7	$ 181.3
Treasury stock acquired, Shares,			1.5		2.9	0.5
Treasury Stock Acquired, Average Cost Per Share			$ 58.21		$ 61.59	$ 60.68
Preferred stock, par value			$ 1	$ 1	$ 1	$ 1	$ 1
Non-cumulative Perpetual Series D Preferred Stock [Member]
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Stock Dividend		4.50%
Preferred stock, par value		$ 1
Preferred stock liquidation preference per depositary share		25
Preferred stock, liquidation preference per share		$ 25,000
Preferred stock, redemption terms					The Company may redeem the Series D preferred stock at its option, subject to regulatory approval, on or after August 15, 2026.
Underwritten registered public offering		$ 300.0
Non-cumulative Perpetual Series A Preferred Stock [Member]
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Stock Dividend	6.25%
Preferred stock redemption price per depositary share	$ 25
Business Bancshares, Inc. [Member]
Business Acquisition Equity Interests Issued Or Issuable [Line Items]
Common stock reissued					2.5