Segment Reporting (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended			9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2011 segment	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Sep. 30, 2011 U.S. Operations	Jun. 30, 2011 U.S. Operations	Sep. 30, 2010 U.S. Operations	Sep. 30, 2011 U.S. Operations	Sep. 30, 2010 U.S. Operations	Sep. 30, 2011 Canadian Operations	Sep. 30, 2010 Canadian Operations	Sep. 30, 2011 Canadian Operations	Sep. 30, 2010 Canadian Operations	Sep. 30, 2011 European Operations.	Sep. 30, 2010 European Operations.	Sep. 30, 2011 European Operations.	Sep. 30, 2010 European Operations.	Sep. 30, 2011 Asia Pacific Operations.	Sep. 30, 2010 Asia Pacific Operations.	Sep. 30, 2011 Asia Pacific Operations.	Sep. 30, 2010 Asia Pacific Operations.	Sep. 30, 2011 Australia	Sep. 30, 2011 Japan
Segment Reporting
Number of operating segments	4
Segment Reporting information
Total revenues	$ 149,419,000	$ 130,396,000	$ 442,114,000	$ 432,408,000		$ 97,999,000		$ 88,138,000	$ 292,402,000	$ 296,135,000	$ 21,682,000	$ 17,364,000	$ 64,350,000	$ 57,294,000	$ 18,611,000	$ 16,771,000	$ 54,487,000	$ 55,080,000	$ 11,127,000	$ 8,123,000	$ 30,875,000	$ 23,899,000
Income (loss) before income tax (benefit) expenses	17,190,000	11,376,000	(200,270,000)	46,185,000		11,471,000		10,131,000	(211,231,000)	47,517,000	5,623,000	4,312,000	15,267,000	15,194,000	1,335,000	381,000	935,000	2,861,000	(1,239,000)	(3,448,000)	(5,241,000)	(19,387,000)
Identifiable assets	2,717,326,000	2,784,100,000	2,717,326,000	2,784,100,000	2,530,853,000	1,229,009,000		1,529,236,000	1,229,009,000	1,529,236,000	131,311,000	105,835,000	131,311,000	105,835,000	660,219,000	535,595,000	660,219,000	535,595,000	696,787,000	613,434,000	696,787,000	613,434,000
Impairment charge on goodwill included in loss before income tax expense			225,035,000	5,375,000			225,000,000		225,035,000														5,400,000
Acquisition related costs			2,500,000
Write-off of capitalized software included in income before income tax expense				(6,091,000)						6,100,000
Restructuring charges included in loss before income tax expense			$ 17,678,000	$ 2,250,000					$ 15,400,000				$ 700,000				$ 1,200,000				$ 300,000			$ 2,500,000