Interest Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Component of Other Expense, Nonoperating [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 3,096	$ (2,436)	$ (2,409)
Interest Expense, Debt	264,080	213,832	39,524
Interest Expense, Other	(189)	4,593	3,766
Interest Costs Incurred, Capitalized	(15,547)	(13,393)	(11,871)
Interest Expense	$ 248,344	$ 205,032	$ 31,419