Acquisitions (Details Textual) (USD $)	12 Months Ended												9 Months Ended	12 Months Ended
	Dec. 31, 2011 Year	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2011 Tradenames [Member] Year	Dec. 31, 2011 Technology/Technical Know-How [Member] Year	Dec. 31, 2011 Customer Relationships [Member] Year	Dec. 31, 2011 6.75% Senior Notes due 2011 [Member]	Dec. 31, 2011 8.625% Senior Notes due 2014 [Member]	Dec. 31, 2011 6.00% Senior Notes due 2016 [Member]	Dec. 31, 2011 9.75% Senior Notes due 2019 [Member]	Dec. 31, 2011 Parent Company [Member]	Sep. 30, 2010 Smith International Incorporate [Member]	Dec. 31, 2011 Smith International Incorporate [Member]	Dec. 31, 2010 Smith International Incorporate [Member]	Dec. 31, 2009 Smith International Incorporate [Member]	Dec. 31, 2011 Geoservices [Member]	Apr. 23, 2010 Geoservices [Member] Year
Business Acquisition [Line Items]
Smith contributed revenue															$ 3,300,000,000
Smith contributed net income															160,000,000
Smith Reported Revenue													6,000,000,000			8,200,000,000
weighted-average life in years	21				25	16	23
Notes Payable								220,000,000	300,000,000	275,000,000	700,000,000
Debt instrument interest rate								6.75%	8.625%	6.00%	9.75%
Debt Instrument, Maturity Date								Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2019
Ownership Interest in Joint Venture	100.00%											40.00%		60.00%
Purchase price																	915,000,000	915,000,000
Intangible Assets Estimated Useful Life																		17
Acquisitions (Textual) [Abstract]
Under merger agreement, shares of Schlumberger in exchange for each Smith share	$ 0.6966
Smith stock options converted to Schlumberger stock options	0.6
Increase goodwill	194,000,000
Goodwill deductible for income tax purposes	200,000,000
Acquired Inventory write-up	155,000,000
Increase (Decrease) in Notes Payable	417,000,000
Acquisitions and minority interest investments, net of cash acquired	610,000,000	212,000,000	514,000,000
Equity Income from joint venture		78,000,000	131,000,000	210,000,000
Gain on Earnings on Equity Interest in Joint Venture Pretax	1,300,000,000
Gain on Earnings on Equity Interest in Joint Venture After Tax	1,200,000,000
Equity Method Investment Dividends or Distributions		$ 50,000,000	$ 106,000,000