Segment Information Entity-Wide Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Customer revenues	$ 142,305	$ 138,443	$ 437,683	$ 431,654
Customer Revenues [Member]
Segment Reporting Information [Line Items]
Customer revenues	142,305	138,443	437,683	431,654
All other [Member]
Segment Reporting Information [Line Items]
Customer revenues	38,398	42,055	106,183	105,356
All other [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
Customer revenues	$ 19,814	$ 15,363	$ 61,291	$ 52,421