Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenues	$ 13,487	$ 12,416	$ 10,263
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)	8,108	7,440	6,141
Selling, general and administrative expenses	2,731	2,509	2,037
Depreciation and amortization expense	359	325	200
Income from operations	2,289	2,142	1,885
Other income (expense), net:
Interest income	115	84	62
Interest expense	(19)	(18)	(3)
Foreign currency exchange gains (losses), net	(30)	(43)	(20)
Other, net	2	(1)	0
Total other income (expense), net	68	22	39
Income before provision for income taxes	2,357	2,164	1,924
Provision for income taxes	(805)	(540)	(485)
Income from equity method investment	1	0	0
Net income	$ 1,553	$ 1,624	$ 1,439
Basic earnings per share	$ 2.56	$ 2.67	$ 2.37
Diluted earnings per share	$ 2.55	$ 2.65	$ 2.35
Weighted average number of common shares outstanding—Basic	607	609	608
Dilutive effect of shares issuable under stock-based compensation plans	3	4	5
Weighted average number of common shares outstanding—Diluted	610	613	613