CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net income	$ 261,285	$ 722,748	$ 372,950
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property and equipment, including internal-use software and website development	477,061	336,680	265,817
Amortization of stock-based compensation	242,417	178,068	85,011
Amortization of intangible assets	317,141	156,458	76,773
Impairment of intangible assets	34,890	7,207	2,842
Deferred income taxes	(14,088)	(21,635)	(79,031)
Foreign exchange (gain) loss on cash, cash equivalents and short-term investments, net	16,253	88,528	79,410
Realized (gain) loss on foreign currency forwards	53,089	(54,226)	5,481
Gain on sale of business	0	(508,810)	0
Non-controlling interest basis adjustment	0	(77,400)	0
Other	7,555	15,865	8,966
Changes in operating assets and liabilities, net of effects from acquisitions and disposals:
Accounts receivable	(276,154)	(198,262)	(157,957)
Prepaid expenses and other assets	(30,198)	97,701	(65,203)
Accounts payable, merchant	184,398	97,248	110,603
Accounts payable, other, accrued expenses and other current liabilities	79,202	194,458	271,454
Tax payable/receivable, net	(100,525)	39,776	39,971
Deferred merchant bookings	261,402	299,534	331,133
Deferred revenue	50,606	(5,893)	18,739
Net cash provided by operating activities	1,564,334	1,368,045	1,366,959
Investing activities:
Capital expenditures, including internal-use software and website development	(749,348)	(787,041)	(328,387)
Purchases of investments	(45,352)	(521,329)	(1,194,210)
Sales and maturities of investments	60,935	410,923	1,162,557
Acquisitions, net of cash acquired	(777)	(2,063,649)	(560,668)
Proceeds from sale of business, net of cash divested and disposal costs	67,088	523,882	0
Net settlement of foreign currency forwards	(53,089)	54,226	(5,481)
Other, net	2,222	11,728	1,932
Net cash used in investing activities	(718,321)	(2,371,260)	(924,257)
Financing activities:
Payment of HomeAway Convertible Notes	(401,424)	0	0
Proceeds from issuance of long-term debt, net of issuance costs	(2,093)	1,441,860	492,894
Purchases of treasury stock	(455,746)	(60,546)	(537,861)
Proceeds from issuance of treasury stock	0	22,575	20,404
Payment of dividends to stockholders	(150,159)	(108,527)	(84,697)
Proceeds from exercise of equity awards and employee stock purchase plan	141,043	97,716	108,121
Sales (purchases) of interest in controlled subsidiaries, net	208,016	(8,518)	(3,272)
Excess tax benefit on equity awards	0	90,855	58,156
Withholding taxes for stock option exercises	(1,282)	(85,033)	0
Other, net	(28,974)	13,817	(5,596)
Net cash provided by (used in) financing activities	(690,619)	1,404,199	48,149
Effect of exchange rate changes on cash and cash equivalents	(34,882)	(127,385)	(109,184)
Net increase in cash and cash equivalents	120,512	273,599	381,667
Cash and cash equivalents at beginning of year	1,676,299	1,402,700	1,021,033
Cash and cash equivalents at end of year	1,796,811	1,676,299	1,402,700
Supplemental cash flow information
Cash paid for interest	153,755	109,507	87,555
Cash paid for interest	$ 124,291	$ 96,834	$ 70,339