Segment and Related Information (Details 1) (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
Segment Reporting Information [Line Items]
Revenues	$ 263,514	$ 261,193	$ 230,822	$ 202,651	$ 194,526	$ 179,278	$ 181,352	$ 160,798	$ 958,180	$ 715,954	$ 490,275
Long-Lived Assets	332,678				296,812				332,678	296,812	307,516
United States [Member]
Segment Reporting Information [Line Items]
Revenues									690,205	516,786	334,986
Long-Lived Assets	252,751				243,194				252,751	243,194	253,630
Canada [Member]
Segment Reporting Information [Line Items]
Revenues									51,713	23,846	13,432
Long-Lived Assets	11,730				12,334				11,730	12,334	12,075
EMEA [Member]
Segment Reporting Information [Line Items]
Revenues									115,319	113,295	115,926
Long-Lived Assets	25,814				26,380				25,814	26,380	27,076
Latin America and Mexico [Member]
Segment Reporting Information [Line Items]
Revenues									76,355	62,027	25,931
Long-Lived Assets	12,920				14,904				12,920	14,904	14,735
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues									24,588
Long-Lived Assets	$ 29,463								$ 29,463