Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Commitments [Line Items]
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	$ 324,000,000
Aggregate amount of quantifiable guarantee agreements in effect for sales of business entities, assets and third party loans	375,000,000
Potential amount of future payments under guarantees	1,900,000,000
Harsh Environment Semisubmersible Drilling Rig [Member]
Commitments [Line Items]
Total cost of the project	764,000,000
Remaining contractual payment is due upon delivery of rig	440,000,000
Ultra-deepwater Drillships [Member]
Commitments [Line Items]
Total cost of the project	655,000,000
Remaining contractual payment is due upon delivery of rig	$ 395,000,000