Business Combinations - Additional Information (Details)	3 Months Ended		6 Months Ended				0 Months Ended				3 Months Ended	6 Months Ended
	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Jun. 24, 2013 NOK	Dec. 31, 2012 USD ($)	Jul. 05, 2013 Discovery Offshore USD ($)	Jun. 30, 2013 Discovery Offshore USD ($)	Jun. 24, 2013 Discovery Offshore USD ($)	Dec. 31, 2012 Discovery Offshore	Jun. 30, 2013 Discovery Offshore General and Administrative Expense USD ($)	Jun. 30, 2013 Discovery Offshore General and Administrative Expense USD ($)	Jun. 24, 2013 Warrants Discovery Offshore USD ($)	Dec. 31, 2012 Discovery Offshore USD ($)	Dec. 31, 2012 Discovery Offshore USD ($)	Jun. 30, 2013 Discovery Offshore Warrants	Jun. 30, 2013 Discovery Offshore
Business Acquisition [Line Items]
Equity Investment	$ 0		$ 0			$ 38,191,000								$ 38,191,000	$ 38,191,000
Ownership percentage															32.00%
Business Acquisition, Percentage of Voting Interests Acquired										52.00%
Cash Paid, net of cash acquired									77,658,000
Ownership In Subsidiary, Percentage							96.00%		84.00%								86.00%
Payments to Acquire Additional Interest in Subsidiaries							15,200,000	4,100,000
Business combination, step acquisition, equity interest in acquiree, fair value									52,000,000
Business Acquisition, Share Price (NOK)					15
Business combination, step acquisition, equity interest in acquiree, percentage										32.00%
Gain on equity investment	14,876,000	0	14,876,000	0					14,900,000
Number of shares of Discovery Offshore stock purchasable by warrants									5,000,000							5,000,000
Business acquisition, preexisting relationship, settlement of accounts receivable									14,300,000
Derivative Assets, Noncurrent													3,500,000
Business acquisition, preexisting relationship, settlement of deferred revenue									5,600,000
Transaction costs											0	3,000,000
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value									$ 26,400,000