v2.4.0.8
Impairment (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended
Jun. 30, 2014
rigs
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Dec. 31, 2013
Jun. 30, 2014
Minimum [Member]
Jun. 30, 2014
Maximum [Member]
Jun. 30, 2014
Floaters [Member]
Jun. 30, 2014
Floaters [Member]
May 31, 2014
Floaters [Member]
Jun. 30, 2014
Discontinued Operations [Member]
Long Lived Assets Held-for-sale [Line Items]                      
Number Of Rigs Committed To Be Sold 5                    
Impairment of Long-Lived Assets to be Disposed of                     $ 546.4
Asset Impairment Charges 991.5 0 991.5 0       991.5 991.5    
Goodwill $ 3,274.0   $ 3,274.0   $ 3,274.0         $ 3,100.0  
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount                   7.00%  
Asset Impairment Charges, Assumptions Used, Terminal Growth Rate 3.50%                    
Asset Impairment Charges, Assumptions Used, Weighted Average Capital Cost 10.50%                    
Asset Impairment Charges, Assumptions Used, Terminal Growth Rate, Reduction Threshold That Would Result In A Fair Value Estimation Below Carrying Value               1.50%      
Asset Impairment Charges, Assumptions Used, Market Days Rate, Reduction Threshold That Would Result In A Fair Value Estimation Below Carrying Value               5.00%      
Asset Impairment Charges, Assumptions Used, Weighted Average Capital Cost, Reduction Threshold That Would Result In A Fair Value Estimation Below Carrying Value               0.50%      
Asset Impairment Charges, Assumptions Used, Price-To-Earnings Multiple           7.5 8.5