Guarantor and Non-Guarantor Supplemental Financial Information - Schedule of Cash Flow Statement Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Net cash provided by operating activities	$ 1,975	$ 1,845	$ 1,549
Investing activities:
Capital expenditures, including internal-use software and website development	(878)	(710)	(749)
Purchases of investments	(1,803)	(1,811)	(45)
Sales and maturities of investments	2,137	1,096	61
Acquisitions, net of cash and restricted cash acquired	(53)	(169)	(1)
Transfers (to) from related parties	0	0	0
Other Investing Activities Net	38	13	16
Net cash used in investing activities	(559)	(1,581)	(718)
Financing activities:
Payment of long-term debt	(500)	0	0
Purchases of treasury stock	(923)	(312)	(456)
Proceeds from issuance of treasury stock	31	0	0
Payment of dividends to stockholders	(186)	(176)	(150)
Proceeds from exercise of equity awards and employee stock purchase plan	166	229	141
Changes in controlled subsidiaries, net	(62)	(18)	208
Transfers (to) from related parties	0	0	0
Other, net	(15)	(25)	(31)
Proceeds from issuance of long-term debt, net of debt issuance costs		990	(2)
Payment of HomeAway Convertible Notes	0	0	(401)
Net cash provided by (used in) financing activities	(1,489)	688	(691)
Effect of exchange rate changes on cash, cash equivalents and restricted cash and cash equivalents	(139)	147	(35)
Net increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents	(212)	1,099	105
Cash, cash equivalents and restricted cash and cash equivalents at beginning of year	2,917	1,818	1,713
Cash, cash equivalents and restricted cash and cash equivalents at end of year	2,705	2,917	1,818
Reportable Legal Entities | Parent
Operating activities:
Net cash provided by operating activities	0	0	0
Investing activities:
Capital expenditures, including internal-use software and website development	0	0	0
Purchases of investments	0	0	0
Sales and maturities of investments	0	0	0
Acquisitions, net of cash and restricted cash acquired	0	0	0
Transfers (to) from related parties	0	0	0
Other Investing Activities Net	0	0	0
Net cash used in investing activities	0	0	0
Financing activities:
Payment of long-term debt	(500)
Purchases of treasury stock	(923)	(312)	(456)
Proceeds from issuance of treasury stock	31
Payment of dividends to stockholders	(186)	(176)	(150)
Proceeds from exercise of equity awards and employee stock purchase plan	166	228	141
Changes in controlled subsidiaries, net	0	0	0
Transfers (to) from related parties	1,415	(725)	468
Other, net	(3)	(5)	(1)
Proceeds from issuance of long-term debt, net of debt issuance costs		990	(2)
Payment of HomeAway Convertible Notes			0
Net cash provided by (used in) financing activities	0	0	0
Effect of exchange rate changes on cash, cash equivalents and restricted cash and cash equivalents	0	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents	0	0	0
Cash, cash equivalents and restricted cash and cash equivalents at beginning of year	0	0	0
Cash, cash equivalents and restricted cash and cash equivalents at end of year	0	0	0
Reportable Legal Entities | Guarantor Subsidiaries
Operating activities:
Net cash provided by operating activities	1,248	1,312	939
Investing activities:
Capital expenditures, including internal-use software and website development	(752)	(546)	(635)
Purchases of investments	(1,720)	(1,222)	0
Sales and maturities of investments	2,063	875	38
Acquisitions, net of cash and restricted cash acquired	(53)	(168)	0
Transfers (to) from related parties	(86)	(5)	(173)
Other Investing Activities Net	35	7	(50)
Net cash used in investing activities	(513)	(1,059)	(820)
Financing activities:
Payment of long-term debt	0
Purchases of treasury stock	0	0	0
Proceeds from issuance of treasury stock	0
Payment of dividends to stockholders	0	0	0
Proceeds from exercise of equity awards and employee stock purchase plan	0	0	0
Changes in controlled subsidiaries, net	0	0	0
Transfers (to) from related parties	(785)	605	(118)
Other, net	(10)	(15)	(2)
Proceeds from issuance of long-term debt, net of debt issuance costs		0	0
Payment of HomeAway Convertible Notes			(401)
Net cash provided by (used in) financing activities	(795)	590	(521)
Effect of exchange rate changes on cash, cash equivalents and restricted cash and cash equivalents	(71)	36	(15)
Net increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents	(131)	879	(417)
Cash, cash equivalents and restricted cash and cash equivalents at beginning of year	1,321	442	859
Cash, cash equivalents and restricted cash and cash equivalents at end of year	1,190	1,321	442
Reportable Legal Entities | Non-Guarantor Subsidiaries
Operating activities:
Net cash provided by operating activities	727	533	610
Investing activities:
Capital expenditures, including internal-use software and website development	(126)	(164)	(114)
Purchases of investments	(83)	(589)	(45)
Sales and maturities of investments	74	221	23
Acquisitions, net of cash and restricted cash acquired	0	(1)	(1)
Transfers (to) from related parties	86	5	173
Other Investing Activities Net	3	6	66
Net cash used in investing activities	(46)	(522)	102
Financing activities:
Payment of long-term debt	0
Purchases of treasury stock	0	0	0
Proceeds from issuance of treasury stock	0
Payment of dividends to stockholders	0	0	0
Proceeds from exercise of equity awards and employee stock purchase plan	0	1	0
Changes in controlled subsidiaries, net	(62)	(18)	208
Transfers (to) from related parties	(630)	120	(350)
Other, net	(2)	(5)	(28)
Proceeds from issuance of long-term debt, net of debt issuance costs		0	0
Payment of HomeAway Convertible Notes			0
Net cash provided by (used in) financing activities	(694)	98	(170)
Effect of exchange rate changes on cash, cash equivalents and restricted cash and cash equivalents	(68)	111	(20)
Net increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents	(81)	220	522
Cash, cash equivalents and restricted cash and cash equivalents at beginning of year	1,596	1,376	854
Cash, cash equivalents and restricted cash and cash equivalents at end of year	$ 1,515	$ 1,596	$ 1,376