v2.4.0.6
Document and Entity Information (USD $)
In Billions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Feb. 14, 2013
Jun. 29, 2012
Entity Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2012    
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus FY    
Trading Symbol NOV    
Entity Registrant Name NATIONAL OILWELL VARCO INC    
Entity Central Index Key 0001021860    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   426,639,780  
Entity Public Float     $ 27.5