Concentrations of Credit Risk and Major Customers (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014 Customer	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk
Concentration of risk, number of customers									5
Entity-Wide Revenue, Major Customer, Amount	$ 202,997	$ 217,092	$ 226,785	$ 224,481	$ 183,348	$ 130,645	$ 133,992	$ 134,273	$ 871,355	$ 582,257	$ 545,745
Sales Revenue, Services, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk
Concentration of risk, number of customers									0	0	1
Baseline percentage for customer concentration of risk									10.00%	10.00%	10.00%
Concentration Risk, Percentage									32.00%	32.00%	39.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk
Concentration Risk, Percentage									28.00%	20.00%