Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation The Company has a stock-based compensation plan known as the National Oilwell Varco, Inc. Long-Term Incentive Plan (the “Plan”). The Plan provides for the granting of stock options, performance-based share awards, restricted stock, phantom shares, stock payments and stock appreciation rights (“SARs”). The number of shares authorized under the Plan was increased during the second quarter of 2016 to 69.4 million. The Plan is now subject to a fungible ratio concept, such that the issuance of stock options and SARs reduces the number of available shares under the Plan on a 1-for-1 basis, and the issuance of other awards reduces the number of available shares under the Plan on a 3-for-1 basis. At September 30, 2016, 31,772,300 shares remain available for future grants under the Plan, all of which are available for grants of stock options, performance-based share awards, restricted stock awards, phantom shares, stock payments and SARs. On February 24, 2016, the Company granted 3,672,411 stock options with a fair value of $6.44 per share and an exercise price of $28.24 per share; 1,732,095 shares of restricted stock and restricted stock units with a fair value of $28.24 per share; performance share awards to senior management employees with potential payouts varying from zero to 341,780 shares; and 4,618,400 SARs with an exercise price of $28.24 and a fair value of $6.44 per SAR. The stock options vest over a three-year period from the grant date while the restricted stock and restricted stock units vest on the third anniversary of the date of grant. The performance share awards can be earned based on performance against established goals over a three-year performance period. The performance share awards are based entirely on a TSR (total shareholder return) goal. Performance against the TSR goal is determined by comparing the performance of the Company’s TSR with the TSR performance of the members of the OSX index for the three-year performance period. The SARs are cash-settled awards and vest over a three-year period from the grant date. Upon exercise of the SARs, the employee is entitled to receive cash payment for the appreciation in the value of our common stock over the exercise price. We account for the cash-settled SARs as liability awards, which require the awards to be revalued at each reporting period. On May 18, 2016, the Company granted 44,520 restricted stock awards with a fair value of $31.45 per share. The awards were granted to non-employee members of the board of directors and vest on the first anniversary of the grant date. Total stock-based compensation for all stock-based compensation arrangements under the Plan was $28 million and $78 million for the three and nine months ended September 30, 2016, respectively, and $21 million and $83 million for the three and nine months ended September 30, 2015, respectively. Included in stock-based compensation for the nine months ended September 30, 2016 and 2015 is $5 million and $18 million, respectively, related to the Voluntary Early Retirement Plan established by the Company in the first quarter of each year. The total income tax benefit recognized in the Consolidated Statements of Income (Loss) for all stock-based compensation arrangements under the Plan was $5 million and $17 million for the three and nine months ended September 30, 2016, respectively, and $7 million and $20 million for the three and nine months ended September 30 2015, respectively.

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.