Common and Preferred Shares (Details Textual) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Sep. 23, 2019
Class of Stock [Line Items]
Common share repurchases authorized (up to) (in shares)				120,000,000
Common shares repurchased (in shares)	20,000,000	46,000,000	7,000,000
Cost basis of common stock repurchased	$ 3,502.0	$ 7,652.0	$ 1,029.0
Common shares remaining under share repurchase authorizations (in shares)	36,000,000
Shares held as treasury shares (in shares)	2,400,000	2,500,000	2,500,000
Cost basis of treasury stock	$ 262.0	$ 271.0	$ 279.0
Preferred shares, authorized, up to (in shares)	20,000,000	20,000,000
Preferred shares, par value (in dollars per share)	$ 1.667	$ 1.667
Redemption price per preferred share (in dollars per share)	1,000,000
Depositary shares redemption amount	$ 1,000
Equity adjustments in connection with redemption of Preferred Shares	$ 0.0	$ 16.0	$ 0.0
Warrants, issued and outstanding (in shares)	0	0	0
Series D Preferred Stock
Class of Stock [Line Items]
Preferred shares, par value (in dollars per share)	$ 1.667
Series B And Series C Preferred Stock
Class of Stock [Line Items]
Payments for redemption of preferred stock		$ 1,600.0
Equity adjustments in connection with redemption of Preferred Shares		16.0
Repurchase Agreements
Class of Stock [Line Items]
Cost basis of common stock repurchased	$ 3,300.0	7,600.0	$ 900.0
Commissions paid included in cost basis of common stock repurchased	$ 4.2	$ 5.6	$ 1.0