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Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
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3 Months Ended | 9 Months Ended | 12 Months Ended | |||||||||||
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Sep. 30, 2013
Country
Rigs
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Dec. 31, 2012
Country
Rigs
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Sep. 30, 2012
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Jun. 30, 2012
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Mar. 31, 2012
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Dec. 31, 2011
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Sep. 30, 2011
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Jun. 30, 2011
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Mar. 31, 2011
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Sep. 30, 2013
Country
Rigs
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Sep. 30, 2012
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Dec. 31, 2012
Customer
Country
Rigs
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Dec. 31, 2011
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Dec. 31, 2010
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| Revenue, Major Customer [Line Items] | ||||||||||||||
| Number of countries with operations | 12 | 12 | ||||||||||||
| Number of countries in which Entity has operated since inception | 50 | 50 | 50 | 50 | ||||||||||
| Barge drilling rigs | 13 | 14 | 13 | 14 | ||||||||||
| Land rings | 23 | 24 | 23 | 24 | ||||||||||
| Percentage accounted for under the equity method | 50.00% | 50.00% | 50.00% | 50.00% | ||||||||||
| Reimbursement cost | $ 16,200,000 | $ 12,100,000 | $ 46,500,000 | $ 29,800,000 | $ 44,900,000 | $ 64,200,000 | $ 40,100,000 | |||||||
| Foreign currency translation impact over net income and retained earnings | 6,400,000 | |||||||||||||
| Collection period | 90 days | |||||||||||||
| Capitalized interest costs of construction of rigs | 700,000 | 2,500,000 | 1,700,000 | 7,900,000 | 10,200,000 | 19,300,000 | 13,500,000 | |||||||
| Net assets held for sale including current asset | 7,485,000 | 6,800,000 | 5,315,000 | 7,485,000 | 6,800,000 | 5,315,000 | ||||||||
| Consumed and replenished period | 1 year | |||||||||||||
| Rate of recognized income tax position being realized | 50.00% | |||||||||||||
| Deposits in domestic bank | 117,100,000 | 12,200,000 | 10,200,000 | 117,100,000 | 12,200,000 | 10,200,000 | ||||||||
| Deposits in foreign banks | 51,800,000 | 34,500,000 | 38,400,000 | 51,800,000 | 34,500,000 | 38,400,000 | ||||||||
| Number of major customer | 2 | |||||||||||||
| Construction revenue | 335,500,000 | 325,900,000 | ||||||||||||
| Contract margin | 48,139,000 | 16,405,000 | 34,038,000 | 46,440,000 | 54,018,000 | 44,399,000 | 49,966,000 | 40,797,000 | 21,204,000 | 118,908,000 | 134,496,000 | 150,901,000 | 156,366,000 | 73,167,000 |
| Share-based awards vesting period | 3 years | |||||||||||||
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Liberty Rig Construction Contract [Member]
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| Revenue, Major Customer [Line Items] | ||||||||||||||
| Contract margin | 11,700,000 | |||||||||||||
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Scenario, Previously Reported [Member]
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| Revenue, Major Customer [Line Items] | ||||||||||||||
| Net assets held for sale including current asset | $ 11,550,000 | $ 11,550,000 | ||||||||||||
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Exxon Neftegas Limited [Member]
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| Revenue, Major Customer [Line Items] | ||||||||||||||
| Percentage of revenue from major customer | 14.30% | 11.80% | ||||||||||||
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Customer Two [Member]
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| Revenue, Major Customer [Line Items] | ||||||||||||||
| Percentage of revenue from major customer | 10.40% | |||||||||||||