Quarterly report pursuant to Section 13 or 15(d)

Assets Held for Sale - Additional Information (Detail)

v2.4.0.6
Assets Held for Sale - Additional Information (Detail) (USD $)
3 Months Ended 3 Months Ended
Mar. 31, 2013
Rigs
Dec. 31, 2012
Mar. 31, 2013
Rig [Member]
Sep. 30, 2012
Kazakhstan [Member]
Rigs
Long Lived Assets Held-for-sale [Line Items]        
Assets held for sale $ 11,526,000 $ 11,550,000 $ 5,300,000  
Number of Land Rigs impacting assets held for sale 5     2
Number of Land Rigs impacting assets held for sale in future 3      
Received in down payment and deposits $ 1,600,000