Segment Reporting (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 segment	Jun. 30, 2012	Dec. 31, 2012
Segment Reporting
Number of operating segments			4
Segment Reporting information
Total revenues	$ 139,293,000	$ 126,910,000	$ 271,343,000	$ 263,285,000
Income (loss) before income tax expense (benefit)	10,770,000	(270,560,000)	21,722,000	(262,066,000)
Identifiable assets	2,874,539,000	2,049,381,000	2,874,539,000	2,049,381,000	2,196,759,000
Impairment charges on goodwill included in loss before income tax benefits		274,285,000		274,285,000
U.S. Operations
Segment Reporting information
Total revenues	84,601,000	81,915,000	165,844,000	166,504,000
Income (loss) before income tax expense (benefit)	4,561,000	(243,909,000)	10,301,000	(240,556,000)
Identifiable assets	1,181,004,000	1,020,351,000	1,181,004,000	1,020,351,000
Duplicate rent charges	1,200,000		2,600,000
One-time charge upon completion of the move			3,900,000
Impairment charges on goodwill included in loss before income tax benefits		245,100,000		245,100,000
U.S. Operations | Restructuring accruals recorded in 2012 and 2011
Segment Reporting information
Reduction in previously recorded restructuring accruals	1,300,000
Canadian Operations
Segment Reporting information
Total revenues	20,105,000	20,319,000	38,649,000	41,150,000
Income (loss) before income tax expense (benefit)	3,795,000	3,521,000	6,371,000	7,383,000
Identifiable assets	95,218,000	79,839,000	95,218,000	79,839,000
Canadian Operations | Restructuring accruals recorded in 2012 and 2011
Segment Reporting information
Reduction in previously recorded restructuring accruals	300,000
European Operations
Segment Reporting information
Total revenues	21,794,000	15,492,000	42,744,000	35,619,000
Income (loss) before income tax expense (benefit)	2,820,000	(27,723,000)	6,321,000	(25,238,000)
Identifiable assets	997,609,000	540,833,000	997,609,000	540,833,000
Impairment charges on goodwill included in loss before income tax benefits		28,500,000		28,500,000
Asia Pacific Operations
Segment Reporting information
Total revenues	12,793,000	9,184,000	24,106,000	20,012,000
Income (loss) before income tax expense (benefit)	(406,000)	(2,449,000)	(1,271,000)	(3,655,000)
Identifiable assets	600,708,000	408,358,000	600,708,000	408,358,000
Impairment charges on goodwill included in loss before income tax benefits		$ 700,000		$ 700,000