Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenue by geographic area
Total revenue	$ 15,782	$ 27,068	$ 17,331	$ 11,299	$ 45,314	$ 37,925	$ 42,563	$ 33,237	$ 71,480	$ 159,039	$ 71,931
United States [Member]
Revenue by geographic area
Revenue from Home country									37,896	29,636	29,511
European countries [Member]
Revenue by geographic area
Revenue from External customers									$ 33,584	$ 129,403	$ 42,420