UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income		$ 720,209	$ 580,638	$ 1,175,832	$ 955,062
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	[1]	139,883	(50,285)	175,688	27,087
Net unrealized gain (loss) on marketable securities	[2]	186,977	(112,038)	532,911	(136,497)
Comprehensive income		$ 1,047,069	$ 418,315	$ 1,884,431	$ 845,652

[1] Foreign currency translation adjustments include tax benefits of $100,608 and $120,341 for the three and six months ended June 30, 2017, respectively, and a tax charge of $26,940 and a tax benefit of $34,156 for the three and six months ended June 30, 2016, respectively, associated with net investment hedges (See Note 10). The remaining balance in foreign currency translation adjustments excludes income taxes as a result of the Company's intention to indefinitely reinvest the earnings of its international subsidiaries outside of the United States (See Note 9).

[2] Net of tax charges of $8,076 and $15,931 for the three and six months ended June 30, 2017, respectively, and net of tax charges of $5,796 and $34,924 for the three and six months ended June 30, 2016, respectively. Net unrealized gain (loss) on marketable securities includes net unrealized gains of $161,389 and $485,077 for the three and six months ended June 30, 2017, respectively, compared to net unrealized losses of $129,406 and $242,558 for the three and six months ended June 30, 2016, respectively, related to the Company's investments in Ctrip.com International Ltd. ("Ctrip"), which are exempt from tax in the Netherlands.