CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Class B Common Stock	Common stock	Additional paid-in capital	Treasury stock	Retained earnings (deficit)	Accumulated other comprehensive income (loss)	Non-redeemable non-controlling interest
Beginning Balance (in shares) at Dec. 31, 2013		12,799,999	192,562,367		75,676,230
Beginning Balance at Dec. 31, 2013	$ 2,258,985	$ 1	$ 19	$ 5,802,140	$ (3,465,675)	$ (209,218)	$ 18,197	$ 113,521
Net income (excludes net loss attributable to redeemable non-controlling interest)	382,640					398,097		(15,457)
Other comprehensive income, net of taxes	(146,506)						(156,971)	10,465
Proceeds from exercise of equity instruments and employee stock purchase plans (in shares)			4,064,829
Proceeds from exercise of equity instruments and employee stock purchase plans	104,599		$ 1	104,598
Tax benefits on equity awards	57,132			57,132
Issuance of common stock in connection with acquisitions (in shares)			175,040
Issuance of common stock in connection with acquisition	0		$ 0	0
Treasury stock activity related to vesting of equity instruments (in shares)					9,689
Treasury stock activity related to vesting of equity instruments	$ (773)				$ (773)
Common stock repurchases (in shares)	7,040,621				7,040,621
Common stock repurchases	$ (537,088)				$ (537,088)
Proceeds from issuance of treasury stock (in shares)					(264,608)
Proceeds from issuance of treasury stock	20,404			14,988	$ 5,416
Cash dividends	(84,697)			(38,833)		(45,864)
Adjustment to the fair value of redeemable non-controlling interests	(259,984)			(116,969)		(143,015)
Change in ownership of non-controlling interest related to trivago initial public offering (IPO)				0
Other changes in ownership of non-controlling interests	25,023			24,090				933
Stock-based compensation expense	69,620			69,620
Other (in shares)					73,464
Other	4,374			4,374	$ 0
Ending Balance (in shares) at Dec. 31, 2014		12,799,999	196,802,236		82,535,396
Ending Balance at Dec. 31, 2014	1,893,729	$ 1	$ 20	5,921,140	$ (3,998,120)	0	(138,774)	109,462
Net income (excludes net loss attributable to redeemable non-controlling interest)	738,165					764,465		(26,300)
Other comprehensive income, net of taxes	(145,479)						(146,120)	641
Proceeds from exercise of equity instruments and employee stock purchase plans (in shares)			3,385,749
Proceeds from exercise of equity instruments and employee stock purchase plans	96,534		$ 0	96,534
Withholding taxes for stock options	(85,033)			(85,033)
Tax benefits on equity awards	89,128			89,128
Issuance of common stock in connection with acquisitions (in shares)			20,195,139
Issuance of common stock in connection with acquisition	2,552,342		$ 2	2,552,340
Treasury stock activity related to vesting of equity instruments (in shares)					127,712
Treasury stock activity related to vesting of equity instruments	$ (15,763)				$ (15,763)
Common stock repurchases (in shares)	525,504				525,504
Common stock repurchases	$ (44,822)				$ (44,822)
Proceeds from issuance of treasury stock (in shares)					(264,841)
Proceeds from issuance of treasury stock	22,575			18,779	$ 3,796
Cash dividends	(108,778)			0		(108,778)
Adjustment to the fair value of redeemable non-controlling interests	(188,579)			(40,558)		(148,021)
Change in ownership of non-controlling interest related to trivago initial public offering (IPO)				0
Sale of controlling interest in eLong	(92,550)			0				(92,550)
Acquisition of non-controlling interest	64,115			0				64,115
Other changes in ownership of non-controlling interests	5,807			(4,198)				10,005
Stock-based compensation expense	147,988			147,988
Other	388			388
Ending Balance (in shares) at Dec. 31, 2015		12,799,999	220,383,124		82,923,771
Ending Balance at Dec. 31, 2015	4,929,767	$ 1	$ 22	8,696,508	$ (4,054,909)	507,666	(284,894)	65,373
Impact of adoption of new accounting guidance related to stock-based compensation	3,011			10,048		(7,037)
Net income (excludes net loss attributable to redeemable non-controlling interest)	283,571					281,848		1,723
Other comprehensive income, net of taxes	(1,551)						(1,551)	0
Proceeds from exercise of equity instruments and employee stock purchase plans (in shares)			3,413,505
Proceeds from exercise of equity instruments and employee stock purchase plans	141,043		$ 0	141,043
Withholding taxes for stock options	(1,282)			(1,282)
Issuance of common stock in connection with acquisitions (in shares)			513,140
Issuance of common stock in connection with acquisition	0		$ 0	0
Treasury stock activity related to vesting of equity instruments (in shares)					174,378
Treasury stock activity related to vesting of equity instruments	$ (19,377)				$ (19,377)
Common stock repurchases (in shares)	3,979,170				3,979,170
Common stock repurchases	$ (436,369)				$ (436,369)
Cash dividends	(149,906)			0		(149,906)
Adjustment to the fair value of redeemable non-controlling interests	(847,601)			(344,064)		(503,537)
Change in ownership of non-controlling interest related to trivago initial public offering (IPO)	0			(32,141)			6,046	26,095
Transfer from redeemable non-controlling interests	1,380,976			0				1,380,976
Proceeds related to trivago IPO, net of fees and expenses	209,903			124,616				85,287
Other changes in ownership of non-controlling interests	274			0				274
Stock-based compensation expense	196,358			196,358
Other	4,286			3,212				1,074
Ending Balance (in shares) at Dec. 31, 2016		12,799,999	224,309,769		87,077,319
Ending Balance at Dec. 31, 2016	$ 5,693,103	$ 1	$ 22	$ 8,794,298	$ (4,510,655)	$ 129,034	$ (280,399)	$ 1,560,802