Segment Information (Entity-Wide Disclosures) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Customer revenues	$ 147,025	$ 143,593
Customer Revenues [Member]
Segment Reporting Information [Line Items]
Customer revenues	147,025	143,593
All other [Member]
Segment Reporting Information [Line Items]
Customer revenues	35,606	26,808
All other [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
Customer revenues	$ 21,676	$ 16,584