Segment Information (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenue	$ 337,047	$ 336,606	$ 646,089	$ 638,828
United States
Segment Reporting Information [Line Items]
Revenue	272,992	271,375	525,190	523,392
Canada
Segment Reporting Information [Line Items]
Revenue	33,614	35,432	62,020	65,258
Other Regions [Domain]
Segment Reporting Information [Line Items]
Revenue	$ 30,441	$ 29,799	$ 58,879	$ 50,178