Nature of Business (Details 2) (Aker Drilling)	1 Months Ended	9 Months Ended
Aug. 31, 2011	Sep. 30, 2011 USD ($) DrillingUnits	Sep. 30, 2011 NOK
Business Combination
Percentage of shares for which cash voluntary offer has been launched	100.00%	100.00%	100.00%
Value per share at which shares offered under cash voluntary offer (in NOK per share)		$ 26.5
Number of Harsh Environment, ultra-deepwater, semi-submersibles operated by an acquired entity		2	2
Number of Ultra-Deepwater drillships currently under construction		2	2
Offer price		$ 1,430,000,000	7,930,000,000
Exchange rate to translate offer price (NOK per dollar)		$ 1.00	5.53

Represents the per share cash voluntary offer to be paid for entity to be acquired in business combination.

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Represents the offer price in terms of equity market capitalization.

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- Definition

The foreign exchange rate used to translate amounts denominated in the functional currency to the reporting currency.

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- Definition

Represents the number of Harsh Environment, ultra-deepwater, semi-submersibles operated by entity to be acquired.

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- Definition

Represents the number of Ultra-Deepwater drillships currently under construction.

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Represents the percentage of shares of entity to be acquired for which a cash voluntary offer has been submitted.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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