Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Restricted cash and cash equivalents (default funds and margin deposits)	$ 5,398	$ 5,074
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	171,535,457	173,418,939
Common stock, shares outstanding (in shares)	164,488,485	166,679,635
Common stock in treasury (in shares)	7,046,972	6,739,304