Segment Information - Schedule of Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 2,559	$ 3,276	$ 2,880	$ 2,508	$ 2,319	$ 2,966	$ 2,586	$ 2,189	$ 11,223	$ 10,060	$ 8,774
Intersegment revenue									0	0	0
Adjusted EBITDA									1,970	1,713	1,616
Depreciation									(676)	(614)	(477)
Amortization of intangible assets									(283)	(275)	(317)
Impairment of goodwill									(86)	0	0
Impairment of intangible assets									(42)	0	(35)
Stock-based compensation									(203)	(149)	(242)
Legal reserves, occupancy tax and other									59	(25)	(27)
Restructuring and related reorganization charges									0	(17)	(43)
Realized (gain) loss on revenue hedges									(25)	(8)	(13)
Operating income	96	672	111	(165)	114	481	103	(73)	714	625	462
Other income (expense), net									(229)	(208)	(185)
Income before income taxes									485	417	277
Provision for income taxes									(87)	(45)	(16)
Net income									398	372	261
Net loss attributable to non-controlling interests									8	6	21
Net income attributable to Expedia Group, Inc.	17	$ 525	$ 1	$ (137)	$ 55	$ 352	$ 57	$ (86)	406	378	282
Corporate & Eliminations
Segment Reporting Information [Line Items]
Revenue									(393)	(414)	(297)
Intersegment revenue									(393)	(414)	(297)
Adjusted EBITDA									(746)	(646)	(631)
Depreciation									(204)	(214)	(165)
Amortization of intangible assets									(283)	(275)	(317)
Impairment of goodwill									(86)
Impairment of intangible assets									(42)		(35)
Stock-based compensation									(203)	(149)	(242)
Legal reserves, occupancy tax and other									59	(25)	(27)
Restructuring and related reorganization charges									0	(17)	(43)
Realized (gain) loss on revenue hedges									0	0	0
Operating income									(1,505)	(1,326)	(1,460)
Core OTA
Segment Reporting Information [Line Items]
Revenue									8,760	7,881	7,084
Impairment of goodwill									(86)
Impairment of intangible assets	$ (42)
Core OTA | Operating Segments
Segment Reporting Information [Line Items]
Revenue									8,760	7,881	7,084
Intersegment revenue									0	0	0
Adjusted EBITDA									2,305	2,057	1,956
Depreciation									(344)	(310)	(256)
Amortization of intangible assets									0	0	0
Impairment of goodwill									0
Impairment of intangible assets									0		0
Stock-based compensation									0	0	0
Legal reserves, occupancy tax and other									0	0	0
Restructuring and related reorganization charges									0	0	0
Realized (gain) loss on revenue hedges									(24)	(8)	(13)
Operating income									1,937	1,739	1,687
trivago
Segment Reporting Information [Line Items]
Revenue									691	752	539
Impairment of goodwill									0
trivago | Operating Segments
Segment Reporting Information [Line Items]
Revenue									1,084	1,166	836
Intersegment revenue									393	414	297
Adjusted EBITDA									16	5	35
Depreciation									(15)	(9)	(7)
Amortization of intangible assets									0	0	0
Impairment of goodwill									0
Impairment of intangible assets									0		0
Stock-based compensation									0	0	0
Legal reserves, occupancy tax and other									0	0	0
Restructuring and related reorganization charges									0	0	0
Realized (gain) loss on revenue hedges									0	0	0
Operating income									1	(4)	28
HomeAway
Segment Reporting Information [Line Items]
Revenue									1,171	906	689
Impairment of goodwill									0
HomeAway | Operating Segments
Segment Reporting Information [Line Items]
Revenue									1,171	906	689
Intersegment revenue									0	0	0
Adjusted EBITDA									288	202	175
Depreciation									(66)	(40)	(18)
Amortization of intangible assets									0	0	0
Impairment of goodwill									0
Impairment of intangible assets									0		0
Stock-based compensation									0	0	0
Legal reserves, occupancy tax and other									0	0	0
Restructuring and related reorganization charges									0	0	0
Realized (gain) loss on revenue hedges									(1)	0	0
Operating income									221	162	157
Egencia
Segment Reporting Information [Line Items]
Revenue									601	521	462
Impairment of goodwill									0
Egencia | Operating Segments
Segment Reporting Information [Line Items]
Revenue									601	521	462
Intersegment revenue									0	0	0
Adjusted EBITDA									107	95	81
Depreciation									(47)	(41)	(31)
Amortization of intangible assets									0	0	0
Impairment of goodwill									0
Impairment of intangible assets									0		0
Stock-based compensation									0	0	0
Legal reserves, occupancy tax and other									0	0	0
Restructuring and related reorganization charges									0	0	0
Realized (gain) loss on revenue hedges									0	0	0
Operating income									$ 60	$ 54	$ 50