Quarterly report pursuant to Section 13 or 15(d)

General - Additional Information (Detail)

v2.4.0.8
General - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 2 Months Ended 6 Months Ended
Jun. 30, 2013
country
rig
Jun. 30, 2012
Jun. 30, 2013
country
rig
Jun. 30, 2012
Dec. 31, 2012
country
Jun. 30, 2013
Exxon Neftegas Limited [Member]
Jun. 30, 2013
Exxon Neftegas Limited [Member]
Jun. 30, 2013
ITS [Member]
Jun. 30, 2013
ITS [Member]
Revenue, Major Customer [Line Items]                  
Number of countries in which Entity has operated since inception 50   50            
Number of countries in which entity operates         12        
Number of countries with international rental tools operations 10   10            
Barge drilling rigs 13   13            
Land rings 23   23            
Number of rigs held for sale 8   8            
Percentage accounted for under the equity method 50.00%   50.00%            
Fair value adjustments for indefinite lived intangible assets                 $ 10.0
Fair value adjustments for finite lived intangible assets                 0.2
Weighted average useful life               3 years 4 months 24 days 3 years
Reimbursement cost 15.4 10.1 30.3 17.7          
Deposits in domestic bank 32.6   32.6   12.2        
Deposits in foreign banks 48.6   48.6   34.5        
Percentage of revenue from major customer           13.90% 14.30%    
Interest costs capitalized $ 0.5 $ 3.0 $ 1.0 $ 5.4