Financial Instruments and Fair Value Disclosures - Assets and Liabilities Measured at Fair Value on Recurring and Nonrecurring Basis (Parenthetical) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) Rigs	Dec. 31, 2014 Rigs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of impaired rigs | $	$ 175.4
Number of rigs sold for scrap | Rigs	9
Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets impaired and sold during the period | $	$ 2.4
Number of rigs sold for scrap | Rigs	5
Number of rigs subject to scrap | Rigs		4
Jack-ups [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of impaired rigs | $	$ 14.2