Segment Information (Details 1) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Segment Reporting Information [Line Items]    
Revenue $ 302,222 $ 274,854
Other Segments    
Segment Reporting Information [Line Items]    
Revenue 20,379 15,108
United States    
Segment Reporting Information [Line Items]    
Revenue 252,018 228,833
Canada    
Segment Reporting Information [Line Items]    
Revenue $ 29,825 $ 30,913