Guarantor and Non-Guarantor Supplemental Financial Information - Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net cash provided by operating activities	$ 2,365,640	$ 1,726,097
Investing activities:
Capital expenditures, including internal-use software and website development	(356,892)	(379,981)
Transfers (to) from related parties		0
Purchases of investments	(991,371)	(20,446)
Sales and maturities of investments	175,319	22,758
Acquisitions, net of cash acquired	(138,215)	0
Other, net	7,218	(16,859)
Net cash used in investing activities	(1,303,941)	(394,528)
Financing activities:
Payment of HomeAway Convertible Notes		(400,443)
Purchases of treasury stock	(114,327)	(328,311)
Transfers (to) from related parties	0	0
Other, net	33,689	(19,735)
Net cash used in financing activities	(80,638)	(748,489)
Effect of exchange rate changes on cash and cash equivalents	96,951	37,145
Net increase in cash and cash equivalents	1,078,012	620,225
Cash and cash equivalents at beginning of period	1,796,811	1,676,299
Cash and cash equivalents at end of period	2,874,823	2,296,524
Parent
Operating activities:
Net cash provided by operating activities	0	0
Investing activities:
Capital expenditures, including internal-use software and website development	0	0
Transfers (to) from related parties		0
Purchases of investments	0	0
Sales and maturities of investments	0	0
Acquisitions, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Financing activities:
Payment of HomeAway Convertible Notes		0
Purchases of treasury stock	(114,327)	(328,311)
Transfers (to) from related parties	67,431	333,702
Other, net	46,896	(5,391)
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Guarantor Subsidiaries
Operating activities:
Net cash provided by operating activities	2,089,301	1,527,488
Investing activities:
Capital expenditures, including internal-use software and website development	(258,561)	(341,818)
Transfers (to) from related parties		(172,731)
Purchases of investments	(825,900)	0
Sales and maturities of investments	149,762	22,758
Acquisitions, net of cash acquired	(138,215)
Other, net	6,233	(19,081)
Net cash used in investing activities	(1,066,681)	(510,872)
Financing activities:
Payment of HomeAway Convertible Notes		(400,443)
Purchases of treasury stock	0	0
Transfers (to) from related parties	(197,265)	(83,370)
Other, net	(7,561)	(3,052)
Net cash used in financing activities	(204,826)	(486,865)
Effect of exchange rate changes on cash and cash equivalents	52,748	21,609
Net increase in cash and cash equivalents	870,542	551,360
Cash and cash equivalents at beginning of period	425,471	841,696
Cash and cash equivalents at end of period	1,296,013	1,393,056
Non-Guarantor Subsidiaries
Operating activities:
Net cash provided by operating activities	276,339	198,609
Investing activities:
Capital expenditures, including internal-use software and website development	(98,331)	(38,163)
Transfers (to) from related parties		172,731
Purchases of investments	(165,471)	(20,446)
Sales and maturities of investments	25,557	0
Acquisitions, net of cash acquired	0
Other, net	985	2,222
Net cash used in investing activities	(237,260)	116,344
Financing activities:
Payment of HomeAway Convertible Notes		0
Purchases of treasury stock	0	0
Transfers (to) from related parties	129,834	(250,332)
Other, net	(5,646)	(11,292)
Net cash used in financing activities	124,188	(261,624)
Effect of exchange rate changes on cash and cash equivalents	44,203	15,536
Net increase in cash and cash equivalents	207,470	68,865
Cash and cash equivalents at beginning of period	1,371,340	834,603
Cash and cash equivalents at end of period	$ 1,578,810	$ 903,468