Segment Information Entity-Wide Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Customer revenues	$ 148,353	$ 149,618	$ 295,378	$ 293,211
Customer Revenues [Member]
Segment Reporting Information [Line Items]
Customer revenues	148,353	149,618	295,378	293,211
All other [Member]
Segment Reporting Information [Line Items]
Customer revenues	32,179	36,493	67,785	63,301
All other [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
Customer revenues	$ 19,801	$ 20,475	$ 41,477	$ 37,058