Acquisitions - Additional Information (Detail) (USD $)	12 Months Ended				1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Schlumberger [Member]	Nov. 15, 2012 Schlumberger [Member] OneSubsea [Member]	Dec. 31, 2012 Schlumberger [Member] OneSubsea [Member]	Dec. 31, 2012 Cameron International Corporation [Member]	Nov. 15, 2012 Cameron International Corporation [Member] OneSubsea [Member]	Apr. 23, 2010 Geoservices [Member]
Business Acquisition [Line Items]
Under merger agreement, shares of Schlumberger in exchange for each Smith share	$ 0.6966
Ownership Interest in Joint Venture	100.00%			40.00%	40.00%		60.00%
Pretax gain on earnings on equity interest in joint venture	$ 1,300,000,000
Pretax gain on earnings on equity interest in joint venture, after-tax	1,200,000,000
Equity income from joint venture			78,000,000
Cash distributions received from the joint venture			50,000,000
Purchase price								600,000,000	915,000,000
Acquisitions and investments, net of cash acquired	845,000,000	610,000,000	212,000,000
Gain on closing of subsea business						$ 1,200,000,000