Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 1,986	$ 1,282	$ 1,396	$ 1,825	$ 2,381	$ 1,512	$ 1,641	$ 1,965	$ 6,489	$ 7,500	$ 7,017
Cost of revenues	656	442	433	563	832	513	510	662
Operating income	454	247	336	570	694	265	434	595	1,607	1,988	1,309
Net income	$ 525	$ 204	$ 328	$ 447	$ 685	$ 260	$ 402	$ 500	$ 1,503	$ 1,848	$ 273
Basic earnings per common share (in dollars per share)	$ 0.68	$ 0.27	$ 0.43	$ 0.58	$ 0.90	$ 0.34	$ 0.53	$ 0.66	$ 1.96	$ 2.43	$ 0.36
Diluted earnings per common share (in dollars per share)	$ 0.68	$ 0.26	$ 0.43	$ 0.58	$ 0.89	$ 0.34	$ 0.52	$ 0.65	$ 1.95	$ 2.40	$ 0.36