Segment Information Revenue by Segment and Category (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Gross Profit		$ 328,067	$ 315,377	$ 637,518	$ 635,479
Third party and other		315,854	294,576	617,426	604,205
Direct		346,765	429,184	718,819	817,990
Total revenue		662,619	723,760	1,336,245	1,422,195
North America [Member]
Gross Profit		233,860	217,174	454,797	433,117
Total revenue	[1]	451,912	516,922	925,269	1,017,735
International [Member]
Gross Profit		94,207	98,203	182,721	202,362
Total revenue	[1]	210,707	206,838	410,976	404,460
Local [Member] | North America [Member]
Gross Profit		179,609	158,812	348,951	322,830
Third party and other		207,534	184,139	408,079	376,292
Local [Member] | International [Member]
Gross Profit		62,303	62,970	121,497	127,191
Third party and other		66,108	67,956	129,683	136,863
Travel [Member] | North America [Member]
Gross Profit		17,755	16,334	32,920	32,046
Third party and other		22,320	21,401	42,782	42,315
Travel [Member] | International [Member]
Gross Profit		9,996	10,484	20,032	21,726
Third party and other		10,796	11,640	21,798	24,091
Third party and other [Member] | Goods [Member] | North America [Member]
Gross Profit		3,207	2,019	4,514	3,692
Third party and other		4,112	2,364	5,816	4,354
Third party and other [Member] | Goods [Member] | International [Member]
Gross Profit		4,506	5,848	8,161	17,551
Third party and other		4,984	7,076	9,268	20,290
Direct [Member] | Goods [Member] | North America [Member]
Gross Profit		33,289	40,009	68,412	74,549
Direct		217,946	309,018	468,592	594,774
Direct [Member] | Goods [Member] | International [Member]
Gross Profit		17,402	18,901	33,031	35,894
Direct		128,819	120,166	$ 250,227	$ 223,216
Sales Revenue, Net [Member]
Concentration of risk, percentage				10.00%	0.00%
United States
Total revenue		442,700	508,800	$ 907,400	$ 1,001,400
UNITED KINGDOM
Total revenue		$ 74,400	$ 78,400	$ 139,900	$ 152,400

[1] North America includes revenue from the United States of $442.7 million and $508.8 million for the three months ended June 30, 2017 and 2016, respectively, and $907.4 million and $1,001.4 million for the six months ended June 30, 2017 and 2016, respectively. International includes revenue from the United Kingdom of $74.4 million and $78.4 million for the three months ended June 30, 2017 and 2016, respectively, and $139.9 million and $152.4 million for the six months ended June 30, 2017 and 2016, respectively. There were no other individual countries that represented more than 10% of consolidated total revenue for the three and six months ended June 30, 2017 and 2016. In prior periods, revenue was attributed to individual countries based on the domicile of the legal entities within the Company's consolidated group that undertook those transactions. The Company updated its attribution of revenue by country in the current period to be based on the location of the customer. Prior period revenue amounts by country have been retrospectively adjusted to reflect that change in attribution.