Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 segment	Mar. 31, 2011	Dec. 31, 2011
Segment Reporting
Number of operating segments	4
Segment Reporting information
Total revenues	$ 136,375	$ 150,078
Income (loss) before income tax expense	8,494	17,131
Identifiable assets	3,808,195	3,260,539	2,178,069
U.S. Operations
Segment Reporting information
Total revenues	84,589	100,511
Income (loss) before income tax expense	3,353	13,549
Identifiable assets	1,657,150	1,871,281
Canadian Operations
Segment Reporting information
Total revenues	20,831	21,839
Income (loss) before income tax expense	3,862	5,117
Identifiable assets	95,324	100,269
European Operations
Segment Reporting information
Total revenues	20,127	18,375
Income (loss) before income tax expense	2,485	506
Identifiable assets	994,500	584,865
Asia Pacific Operations
Segment Reporting information
Total revenues	10,828	9,353
Income (loss) before income tax expense	(1,206)	(2,041)
Identifiable assets	$ 1,061,221	$ 704,124