Quarterly Financial Data (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Net revenues	$ 2,322	$ 2,099	$ 2,110	$ 2,061	$ 2,323	$ 2,150	$ 2,168	$ 2,149	$ 8,592	$ 8,790	$ 8,257
Gross profit	1,829	1,666	1,676	1,650	1,881	1,737	1,757	1,752	6,821	7,127	6,765
Income (loss) from continuing operations	523	545	430	449	729	509	458	(2,561)	1,947	(865)	2,067
Income (loss) from discontinued operations, net of income taxes	(46)	(6)	(347)	177	294	164	218	235	(222)	911	789
Net income	$ 477	$ 539	$ 83	$ 626	$ 1,023	$ 673	$ 676	$ (2,326)	$ 1,725	$ 46	$ 2,856
Income (loss) per share - basic:
Continuing operations (in usd per share)	$ 0.44	$ 0.45	$ 0.35	$ 0.37	$ 0.59	$ 0.41	$ 0.36	$ (2.01)	$ 1.61	$ (0.69)	$ 1.60
Discontinued operations (in usd per share)	(0.04)	0.00	(0.28)	0.14	0.24	0.13	0.18	0.19	(0.18)	0.73	0.60
Net income per share - basic (in usd per share)	0.40	0.45	0.07	0.51	0.83	0.54	0.54	(1.82)	1.43	0.04	2.20
Income (loss) per share - diluted:
Continuing operations (in usd per share)	0.43	0.45	0.35	0.37	0.59	0.41	0.36	(2.01)	1.60	(0.69)	1.58
Discontinued operations (in usd per share)	(0.04)	0.00	(0.28)	0.14	0.23	0.13	0.17	0.19	(0.18)	0.73	0.60
Net income per share - diluted (in usd per share)	$ 0.39	$ 0.45	$ 0.07	$ 0.51	$ 0.82	$ 0.54	$ 0.53	$ (1.82)	$ 1.42	$ 0.04	$ 2.18
Weighted average shares:
Basic (in shares)	1,191	1,210	1,217	1,216	1,230	1,242	1,258	1,276	1,208	1,251	1,295
Diluted (in shares)	1,204	1,223	1,225	1,229	1,241	1,251	1,267	1,276	1,220	1,251	1,313