Concentrations of Credit Risk and Major Customers (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) Customer	Dec. 31, 2014 USD ($) Customer	Dec. 31, 2013 USD ($) Customer
Concentration Risk
Concentration of risk, number of customers									5
Entity-Wide Revenue, Major Customer, Amount | $	$ 174,605	$ 182,533	$ 191,684	$ 187,523	$ 202,997	$ 217,092	$ 226,785	$ 224,481	$ 736,345	$ 871,355	$ 582,257
Sales Revenue, Services, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk
Concentration of risk, number of customers									0	0	0
Baseline percentage for customer concentration of risk									10.00%	10.00%	10.00%
Concentration Risk, Percentage									36.00%	32.00%	32.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk
Concentration Risk, Percentage									33.00%	28.00%