Acquisitions, Disposals and Other Transactions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			3 Months Ended
	Jul. 31, 2015	Nov. 30, 2014	Aug. 31, 2014	Sep. 30, 2015
REA Group [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Interest acquired				20.00%
Company ownership percentage				61.60%
Harlequin Enterprises Limited [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity			$ 414
Business acquisition purchase price allocation, cash			19
Business acquisition purchase price allocation, net tangible assets			115
Business acquisition purchase price allocation, net intangible assets			165
Business acquisition purchase price allocation, non-amortizable intangible assets			105
Business acquisition purchase price allocation, amortizable intangible assets			$ 60
Finite lived intangible assets, weighted average useful life			5 years
Business acquisition purchase price allocation, deferred tax liability			$ 35
Business acquisition purchase price allocation, goodwill amount			$ 185
Checkout 51 [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity, cash paid	$ 13
Checkout 51 [Member] | Maximum [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Future consideration primarily related to payments contingent	$ 28
Move Inc [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity, cash paid		$ 864
Business acquisition, cost of acquired entity		892
Business acquisition purchase price allocation, cash		108
Business acquisition purchase price allocation, net intangible assets		$ 216
Shares purchase price		$ 21.00
Fair value of assumed outstanding equity-based compensation awards		$ 67
Business acquisition pre-combination services		28
Consideration transferred for future services		$ 39
Business combination, weighted average remaining service period		2 years 6 months
Business acquisition, cash paid for outstanding indebtedness		$ 129
Move Inc [Member] | U.S. Federal [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Net operating loss carryforwards		947
Net operating loss carryforwards, tax-effected		$ 332
Valuation allowances				$ 484
Unrecognized tax benefits				484
Valuation allowances, tax-effected				170
Unrecognized benefits, tax-effected				170
Expected net operating loss carryforwards to be utilized				463
Net deferred tax asset				162
Increase in expected net operating loss carryforwards				167
Increase in expected net operating loss carryforwards tax-effected				58
Expected net operating loss carryforwards				630
Expected net operating loss carryforwards tax-effected				220
Move Inc [Member] | Trademarks [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, non-amortizable intangible assets				116
Move Inc [Member] | Customer Relationships Other Trade Names And Listing Service Agreements [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets				$ 100
Useful life of amortizable intangible assets				15 years
Move Inc [Member] | Technology-Based Intangible Assets [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets				$ 39
Useful life of amortizable intangible assets				4 years