Geographical Information (Details) (USD $) In Thousands, unless otherwise specified	3 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	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue and long-lived assets by geographical segments
Revenues	$ 103,610	$ 93,818	$ 96,336	$ 92,849	$ 108,301	$ 84,594	$ 67,852	$ 63,510	$ 386,613	$ 324,257	$ 241,328
United States
Revenue and long-lived assets by geographical segments
Revenues									282,762	263,956	236,959
North America (Excluding U.S.)
Revenue and long-lived assets by geographical segments
Revenues									23,738	17,021
Europe, Middle East and Africa
Revenue and long-lived assets by geographical segments
Revenues									51,507	29,716	3,770
Asia Pacific
Revenue and long-lived assets by geographical segments
Revenues									21,677	9,318	434
Latin America
Revenue and long-lived assets by geographical segments
Revenues									$ 6,929	$ 4,246	$ 165
Foreign Jurisdictions
Revenue and long-lived assets by geographical segments
Percentage of revenue or about the percentage of revenue									27.00%