Long-Term Debt Long-Term Debt Schedule (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Secured Debt	$ 741,000	$ 774,000
Unamortized Debt Issuance Expense	(17,781)	(18,500)
Long-term Debt	723,219	755,508
$150 Million Revolving Credit Facility, Due June 2020 [Member]
Debt Instrument [Line Items]
Secured Debt	34,000	50,000
$825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Secured Debt	$ 707,000	$ 724,000