Other Financial Statement Disclosures - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) drilling_unit	Sep. 30, 2015 USD ($) drilling_unit	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Supplemental Cash Flow Information
Accrued capital expenditures			$ 23,200,000	$ 36,500,000
Interest capitalized in connection with rig construction projects	$ 0	$ 0	$ 0	$ 16,200,000
Income Taxes
Effective tax rate	181.20%	(12.20%)	4.10%	256.20%
Provision (benefit) for income taxes	$ (12,200,000)	$ 25,900,000	$ 14,700,000	$ 50,900,000
Decrease in income tax expense as compared to prior year periods	38,100,000		36,200,000
Property, Plant and Equipment [Line Items]
Asset impairment charges	34,300,000	329,800,000	34,300,000	329,800,000
Charges related to contract termination		$ 2,600,000		$ 7,600,000
Reversal of estimated settlement liaibility	$ 1,400,000		$ 1,400,000
Jack-up Rigs [Member]
Property, Plant and Equipment [Line Items]
Number of drilling units impaired | drilling_unit	5	10