Notes Payable, Interest Expense and Commitments and Contingencies (Interest Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Detail of interest expensed and incurred
Total interest incurred	$ 6,337	$ 6,838	$ 19,395	$ 21,740
Interest capitalized	(544)	(237)	(1,459)	(237)
Total interest expense	$ 5,793	$ 6,601	$ 17,936	$ 21,503