Acquisitions and Divestitures - Additional Information - 2015 Activity - Australia Divestiture (Detail) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended	0 Months Ended
	Jun. 30, 2014	Dec. 31, 2014	Mar. 31, 2015	Apr. 08, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effective date of acquisition	May 01, 2014	Oct. 01, 2014
LNG Projects [Member] | Apache Energy Limited [Member] | Australia [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effective date of acquisition			Oct. 01, 2014
LNG Projects [Member] | Apache Energy Limited [Member] | Australia [Member] | Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration for subsidiary				$ 2,100,000,000
Estimated loss on divestiture				$ 1,000,000,000