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Pension and Other Benefit Plans - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]      
Fair value of excess of plan assets, projected benefit obligation $ 9.9    
Projected benefit obligation plan assets 11.0    
Accumulated benefit obligation plan assets $ 10.6    
Frequency of asset performance monitored, years 5 years    
Expected contributions to postretirement benefit plans $ 25.0    
Expenses for deferred benefit programs $ 435.0 $ 413.0 $ 445.0
US Employees Postretirement Benefits Other Than Pensions      
Defined Benefit Plan Disclosure [Line Items]      
Retirement coverage plan, description Effective April 1, 2015, Schlumberger changed the way it provides healthcare coverage to certain retirees who are age 65 and over. Under the amended plan, these retirees transferred to individual coverage under the Medicare Exchange. Schlumberger subsidizes 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 by more than 5% in any given year.    
US Employees Postretirement Benefits Other Than Pensions | Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Compensation increases 5.00%    
Postretirement medical plan | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Investment of assets in government and government-related debt securities under US postretirement medical plan 57.00%    
Postretirement medical plan | Government and government-related debt securities      
Defined Benefit Plan Disclosure [Line Items]      
Investment of assets in government and government-related debt securities under US postretirement medical plan 43.00%