Concentration of Business Risk (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
Revenue by geographic area
Total revenue	$ 9,959	$ 18,416	$ 42,885	$ 46,946
North America [Member]
Revenue by geographic area
Total revenue	3,400	4,785	13,514	15,525
Europe [Member]
Revenue by geographic area
Total revenue	5,282	9,488	21,579	22,100
South America [Member]
Revenue by geographic area
Total revenue	978	3,860	6,097	8,542
Asia [Member]
Revenue by geographic area
Total revenue	$ 299	$ 283	$ 998	$ 779