Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenue	$ 1,439	$ 1,324	$ 4,262	$ 3,938
Expenses:
Operating-related expenses	438	419	1,363	1,241
Selling and general expenses	330	458	975	1,111
Depreciation	22	20	63	64
Amortization of intangibles	23	17	71	40
Total expenses	813	914	2,472	2,456
Gain on dispositions	(722)	0	(722)	(11)
Operating profit	1,348	410	2,512	1,493
Interest expense, net	39	30	122	62
Income before taxes on income	1,309	380	2,390	1,431
Provision for taxes on income	386	99	731	439
Net income	923	281	1,659	992
Less: net income attributable to noncontrolling interests	(31)	(29)	(90)	(83)
Net income	$ 892	$ 252	$ 1,569	$ 909
Net income:
Basic (in dollars per share)	$ 3.39	$ 0.93	$ 5.94	$ 3.33
Diluted (in dollars per share)	$ 3.36	$ 0.92	$ 5.89	$ 3.30
Weighted-average number of common shares outstanding:
Basic (in shares)	262.9	271.3	264.1	272.6
Diluted (in shares)	265.3	274.4	266.4	275.4
Actual shares outstanding at period end (in shares)			259.1	270.3
Dividend declared per common share (in dollars per share)	$ 0.36	$ 0.33	$ 1.08	$ 0.99