Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Millions, $ 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]
Total net revenues	$ 3,287	$ 3,317	$ 3,245	$ 3,118	$ 3,179	$ 3,292	$ 3,196	$ 3,168	$ 12,967	$ 12,835	$ 12,132
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	534	641	587	470	652	588	548	696
Net income	$ 463	$ 543	$ 492	$ 395	$ 539	$ 503	$ 462	$ 594	$ 1,893	$ 2,098	$ 1,480
Earnings Per Share [Abstract]
Net income (in dollars per basic share)	$ 3.59	$ 4.09	$ 3.61	$ 2.85	$ 3.81	$ 3.48	$ 3.14	$ 3.97	$ 14.12	$ 14.41	$ 9.60
Net income (in dollars per diluted share)	$ 3.53	$ 4.04	$ 3.57	$ 2.82	$ 3.76	$ 3.43	$ 3.10	$ 3.91	$ 13.92	$ 14.20	$ 9.44
Weighted average common shares outstanding
Basic	129.0	132.7	136.1	138.8	141.5	144.4	147.0	149.5	134.1	145.6	154.1
Diluted	131.3	134.5	138.0	140.1	143.2	146.5	149.0	152.1	136.0	147.7	156.7
Cash dividends declared per common share	$ 0.97	$ 0.97	$ 0.97	$ 0.90	$ 0.90	$ 0.90	$ 0.90	$ 0.83