Pension and Other Benefit Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Frequency of asset performance monitored, years	5 years
Anticipated contributions to postretirement benefit plans	$ 400
Expenses for deferred benefit programs	$ 749	$ 671	$ 620
US Employees Postretirement Benefits Other Than Pensions
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Retirement coverage plan, description	During the fourth quarter of 2014 Schlumberger announced that, effective April 1, 2015, it will change the way it provides healthcare coverage to certain retirees who are age 65 and over. Under the amended plan, these retirees will transfer to individual coverage under the Medicare Exchange. Schlumberger will subsidize the cost of the program by providing these retirees with a Health Reimbursement Account. The annual subsidy may be increased based on medical cost inflation, but it will not be increased more than 5% in any given year.
Percentage of accumulated benefit obligation	66.00%
US Employees Postretirement Benefits Other Than Pensions | Maximum
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Compensation increases	5.00%
Postretirement medical plan | Government and government-related debt securities
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Investment of assets in government and government-related debt securities under US postretirement medical plan	40.00%
Postretirement medical plan | United States | Equity securities
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Investment of assets in government and government-related debt securities under US postretirement medical plan	60.00%