Business Combinations - Additional Information (Details)	3 Months Ended		9 Months Ended			0 Months Ended	9 Months Ended			9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Dec. 31, 2012 USD ($)	Jun. 24, 2013 Discovery Offshore USD ($)	Sep. 30, 2013 Discovery Offshore USD ($)	Sep. 30, 2013 Discovery Offshore NOK	Jun. 24, 2013 Discovery Offshore NOK	Sep. 30, 2013 Discovery Offshore Gain on Equity Investment USD ($)	Sep. 30, 2013 Discovery Offshore General and Administrative Expense USD ($)	Sep. 30, 2013 Discovery Offshore General and Administrative Expense USD ($)	Jun. 24, 2013 Warrants Discovery Offshore USD ($)	Dec. 31, 2012 Discovery Offshore USD ($)	Sep. 30, 2013 Discovery Offshore Warrants	Jun. 24, 2013 Discovery Offshore Warrants NOK	Dec. 31, 2012 Discovery Offshore Warrants NOK
Business Acquisition [Line Items]
Equity Investment	$ 0		$ 0		$ 38,191,000									$ 38,191,000
Ownership percentage														32.00%
Business Acquisition, Percentage of Voting Interests Acquired						52.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage						84.00%
Cash Paid, net of cash acquired						77,658,000
Business Acquisition, Effective Date of Acquisition							Jun. 24, 2013
Ownership In Subsidiary, Percentage								100.00%
Share Price																15.00	13.00
Payments to Acquire Additional Interest in Subsidiaries							26,300,000
Business combination, step acquisition, equity interest in acquiree, fair value						52,000,000
Business Acquisition, Share Price (NOK)								15	15
Business combination, step acquisition, equity interest in acquiree, percentage						32.00%
Gain on equity investment	0	0	14,876,000	0						14,876,000
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
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value						26,400,000
Business Acquisition, Transaction Costs											$ 300,000	$ 3,300,000