Supplemental Financial Information (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Examination [Line Items]
Bad debt (recovery) expense	$ (6,713,000)	$ (9,789,000)	$ 9,746,000
Amount of bad debts recorded in prior periods and subsequently recovered	12,300,000	9,700,000	900,000
Supplemental financial information (Textual) [Abstract]
Amount of bad debts reserved for and recovered in the current year	200,000
Interest paid on long-term debt	82,900,000	83,500,000	39,500,000
Construction milestone payments	14,600,000	154,400,000
Interest on Internal Revenue Service Assessment		900,000
Unpaid accrued capital expenditures	37,300,000	28,900,000
Cash payments of capital expenditures accrued in the prior year	28,900,000	64,900,000	59,400,000
Income tax benefits related to employee stock plan exercises			1,000,000
Egypt Customers Current [Member]
Income Tax Examination [Line Items]
Bad debt (recovery) expense	5,700,000	0	10,700,000
Egypt Customer Previous [Member]
Income Tax Examination [Line Items]
Amount of bad debts recorded in prior periods and subsequently recovered	3,700,000	5,500,000
North Sea Customer [Member]
Income Tax Examination [Line Items]
Amount of bad debts recorded in prior periods and subsequently recovered	8,400,000	4,200,000
Amount of trade accounts receivable written off against allowance for doubtful accounts	18,400,000
Domestic Country [Member]
Income Tax Examination [Line Items]
Income taxes paid	94,800,000	427,500,000	252,400,000
Foreign Country [Member]
Income Tax Examination [Line Items]
Income taxes paid, net	150,500,000	128,500,000	176,200,000
State and Local Jurisdiction [Member]
Income Tax Examination [Line Items]
Income taxes paid, net	$ 200,000	$ 100,000	$ 200,000