Debt (Schedule of Long-term Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term Debt	$ 395,000	$ 395,000
Deferred Finance Costs, Net	7,449	7,783
Long-term Debt, Excluding Current Maturities	387,551	387,217
Senior Notes [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt	300,000	300,000
Revolving Credit Facility [Member] | Senior secured revolving credit facility [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 95,000	$ 95,000