Property and Equipment - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Capital expenditures	$ 423	$ 2,100	$ 2,500
Capitalized interest on construction-in-progress	$ 25	47	115
Paragon Offshore [Member]
Property, Plant and Equipment [Line Items]
Capital expenditures		150	359
Depreciation expense		$ 236	$ 368