Segment Reporting (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 segment	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting
Number of operating segments	4
Segment Reporting information
Total revenues	$ 132,050,000	$ 136,375,000
Income (loss) before income tax expense (benefit)	10,952,000	8,494,000
Identifiable assets	4,001,363,000	3,808,195,000	2,196,759,000
U.S. Operations
Segment Reporting information
Total revenues	81,243,000	84,589,000
Income (loss) before income tax expense (benefit)	5,740,000	3,353,000
Identifiable assets	1,888,817,000	1,657,150,000
Duplicate rent charges	1,300,000
Canadian Operations
Segment Reporting information
Total revenues	18,544,000	20,831,000
Income (loss) before income tax expense (benefit)	2,576,000	3,862,000
Identifiable assets	97,632,000	95,324,000
European Operations
Segment Reporting information
Total revenues	20,950,000	20,127,000
Income (loss) before income tax expense (benefit)	3,501,000	2,485,000
Identifiable assets	1,271,052,000	994,500,000
Asia Pacific Operations
Segment Reporting information
Total revenues	11,313,000	10,828,000
Income (loss) before income tax expense (benefit)	(865,000)	(1,206,000)
Identifiable assets	$ 743,862,000	$ 1,061,221,000