CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Statement of Income Captions [Line Items]
Income (loss) from continuing operations	$ 1,988	$ 28,601	$ (166,209)
Other comprehensive income (loss) from continuing operations:
Net change in unrealized gain (loss) on foreign currency translation adjustment	3,332	(27,287)	5,988
Other comprehensive income (loss) from discontinued operations - Foreign currency translation adjustments:
Comprehensive income (loss)	4,585	419	(176,477)
Comprehensive income attributable to noncontrolling interests	(13,067)	(12,587)	(11,264)
Comprehensive income (loss) attributable to Groupon, Inc.	(8,482)	(12,168)	(187,741)
Tax effect	34	0	43
Continuing Operations
Condensed Statement of Income Captions [Line Items]
Income (loss) from continuing operations	1,988	28,601	(166,209)
Other comprehensive income (loss) from continuing operations:
Net change in unrealized gain (loss) on foreign currency translation adjustment	3,332	(10,776)	8,361
Net change in unrealized gain (loss) on defined benefit pension plan	0	585	928
Net unrealized gain (loss) during the period	(841)	(1,109)	(70)
Reclassification adjustment for realized (gain) loss on investment included in income (loss) from continuing operations	106	1,603	0
Net change in unrealized gain (loss) on available-for-sale securities	(735)	494	(70)
Other comprehensive income (loss) from discontinued operations - Foreign currency translation adjustments:
Other comprehensive income (loss)	2,597	(9,697)	9,219
Comprehensive income (loss)	4,585	18,904	(156,990)
Discontinued Operations, Disposed of by Sale
Other comprehensive income (loss) from continuing operations:
Net change in unrealized gain (loss) on available-for-sale securities	0	(16,511)	(2,373)
Income (loss) from discontinued operations	0	(1,974)	(17,114)
Other comprehensive income (loss) from discontinued operations - Foreign currency translation adjustments:
Net unrealized gain (loss) during the period	0	(1,793)	(9,305)
Reclassification adjustment included in income (loss) from discontinued operations	0	(14,718)	6,932
Other comprehensive income (loss)	$ 0	$ (18,485)	$ (19,487)