Summary of Significant Accounting Policies (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	Dec. 31, 2011
Geographic segment and long-term assets geographic segment
Revenues	$ 55,845	$ 46,305	$ 159,717	$ 137,264
Long-term assets	41,658		41,658		42,169
Specified percentage of net revenue required for separate reporting of countries' revenue			5.00%
United States of America [Member]
Geographic segment and long-term assets geographic segment
Revenues	37,315	30,377	105,172	87,554
Long-term assets	33,460		33,460		33,697
Japan [Member]
Geographic segment and long-term assets geographic segment
Revenues	7,170	6,167	21,441	17,947
Long-term assets	450		450		566
United Kingdom [Member]
Geographic segment and long-term assets geographic segment
Revenues	3,821	1,866	9,775	9,809
Long-term assets	7,748		7,748		7,906
Switzerland [Member]
Geographic segment and long-term assets geographic segment
Revenues	2,955	2,390	8,779	7,881
Other [Member]
Geographic segment and long-term assets geographic segment
Revenues	$ 4,584	$ 5,505	$ 14,550	$ 14,073