Concentration of Business Risk (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								6 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue by geographic area
Total revenue	$ 13,983	$ 10,262	$ 15,697	$ 17,229	$ 14,321	$ 18,416	$ 15,134	$ 13,396	$ 32,926	$ 43,188	$ 46,946	$ 57,171	$ 61,267	$ 52,073
North America [Member]
Revenue by geographic area
Total revenue												18,395	18,971	11,275
Europe [Member]
Revenue by geographic area
Total revenue												30,418	29,851	32,376
South America [Member]
Revenue by geographic area
Total revenue												7,224	11,300	7,287
Asia [Member]
Revenue by geographic area
Total revenue												$ 1,134	$ 1,145	$ 1,135