Reporting Segments Schedule of revenues by geographic area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenue	$ 183,890	$ 220,260	$ 226,693	$ 233,524	$ 236,553	$ 244,662	$ 246,821	$ 257,458	$ 864,367	$ 985,494	$ 1,122,972
US
Segment Reporting Information [Line Items]
Total revenue									686,526	738,400	798,285
Canada
Segment Reporting Information [Line Items]
Total revenue									117,712	139,068	206,410
UK
Segment Reporting Information [Line Items]
Total revenue									59,302	105,784	113,681
Other
Segment Reporting Information [Line Items]
Total revenue									$ 827	$ 2,242	$ 4,596