Commitments and Contingencies Warranty 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
Warranty expense	$ 444	$ 27,775	$ 8,141	$ 37,939