ACQUISITIONS (Narrative) (Details) - USD ($)			3 Months Ended	12 Months Ended
		Jul. 24, 2014	Jun. 30, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Carrying Value					$ 6,170,522,000	$ 6,158,443,000
Impairment of goodwill					940,700,000	0	$ 0
Acquisition related costs							6,900,000
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Payments to acquire business, net of cash acquired			$ 98,000,000			75,000,000
Contingent consideration, liability					9,000,000		10,700,000
Contingent consideration arrangements, low range of outcomes, value					0
Contingent consideration arrangements, high range of outcomes, value					90,000,000
Cash paid to settle contingent consideration						18,400,000
Cash paid to settle contingent consideration, financing activities						10,700,000
Cash paid to settle contingent consideration, operating activities						$ 7,700,000
OpenTable
Business Acquisition [Line Items]
Purchase price, total consideration		$ 2,500,000,000					2,529,000,000
Purchase price net of cash acquired		$ 2,400,000,000
Business acquisition, share price (in dollars per share)		$ 103.00
Acquisition date fair value of assumed equity awards		$ 95,000,000
Impairment of goodwill					$ 940,700,000
Identifiable intangible assets	[1]						1,435,000,000
Cash acquired from acquisition							$ 126,000,000
Intangible weighted average useful life							18 years 10 months
Deferred tax liabilities, intangible assets							$ 543,000,000
Trade names | OpenTable
Business Acquisition [Line Items]
Identifiable intangible assets							$ 1,100,000,000
Amortization Period							20 years
Customer Relationships | OpenTable
Business Acquisition [Line Items]
Identifiable intangible assets							$ 290,000,000
Amortization Period							15 years
Technology-Based Intangible Assets | OpenTable
Business Acquisition [Line Items]
Identifiable intangible assets							$ 15,000,000
Amortization Period							5 years
Revolving Credit Facility | OpenTable
Business Acquisition [Line Items]
Carrying Value		$ 995,000,000
Scenario, forecast | Subsequent Event | Momondo Group
Business Acquisition [Line Items]
Payments to acquire business				$ 550,000,000

[1] Acquired definite-lived intangibles, with a weighted-average life of 18.8 years, consisted of trade names of $1.1 billion with an estimated useful life of 20 years, supply and distribution agreements of $290 million with an estimated useful life of 15 years, and technology of $15 million with estimated useful life of 5 years.