Common and Preferred Shares (Details Textual) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Mar. 08, 2023
Class of Stock [Line Items]
Common share repurchases authorized (up to) (in shares)				120.0
Common shares repurchased (in shares)	22.0	20.0	46.0
Cost basis of common stock repurchased	$ 3,650	$ 3,502	$ 7,652
Common shares remaining under share repurchase authorizations (in shares)	99.0
Shares held as treasury shares (in shares)	2.3	2.4	2.5
Cost basis of treasury stock	$ 252	$ 262	$ 271
Preferred shares, authorized, up to (in shares)	20.0	20.0
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 (in dollars per share)	$ 1,000
Equity adjustments in connection with redemption of Preferred Shares	$ 0	$ 0	16
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
Equity adjustments in connection with redemption of Preferred Shares			16
Repurchase Agreements
Class of Stock [Line Items]
Cost basis of common stock repurchased	$ 3,500	3,300	7,600
Commissions and excise tax paid included in cost basis of common stock repurchased	$ 32
Commissions paid included in cost basis of common stock repurchased		$ 4	$ 6