Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net loss from continuing operations	$ 3,802	$ (34,447)	$ (22,470)	$ (126,754)
Other comprehensive (loss) income, net of tax:
Reclassification of amount included in net income (loss) from continuing operations				(200)
Net change in unrealized gain (loss) - Foreign Currency Translation			(27,259)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	0	583	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax	0	23	2	69
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	0	(23)	585	(69)
Net change in unrealized gain (loss), net, on AFS	(225)	(16)	(938)	(184)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	0	0	(1,341)	0
Comprehensive loss	(2,319)	(34,952)	(53,174)	(144,193)
Net loss from discontinued operations	(862)	(1,345)	(1,751)	(6,365)
Comprehensive income attributable to noncontrolling interests	(2,881)	(2,184)	(9,460)	(8,880)
Comprehensive loss attributable to Groupon Inc.	(5,200)	(37,136)	(62,634)	(153,073)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Other comprehensive (loss) income, net of tax:
Net change in unrealized gain (loss), net, on AFS	(225)	(16)	(2,279)	(184)
Other comprehensive income (loss)			585
Continuing Operations [Member]
Other comprehensive (loss) income, net of tax:
Net unrealized gain (losses) during the period	(5,034)	11,358	(10,561)	7,290
Reclassification of amount included in net income (loss) from continuing operations	0	221	(187)	(7,776)
Net change in unrealized gain (loss) - Foreign Currency Translation	(5,034)	11,579	(10,748)	(486)
Other comprehensive income (loss)	(5,259)	11,586	(12,442)	(601)
Comprehensive loss	(1,457)	(22,861)	(34,912)	(127,355)
Discontinued Operations, Disposed of by Sale [Member]
Other comprehensive (loss) income, net of tax:
Net unrealized gain (losses) during the period	0	(10,746)	(1,793)	(10,473)
Reclassification of amount included in net income (loss) from continuing operations	0	0	(14,718)	0
Net change in unrealized gain (loss) - Foreign Currency Translation	0	(10,746)	(16,511)	(10,473)
Other comprehensive income (loss)	$ (862)	$ (12,091)	$ (18,262)	$ (16,838)