Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Liabilities, Quantitative Information
Long-term Debt	$ 691,930	$ 755,508
Unamortized Debt Issuance Expense	17,070	$ 18,500
Level 2 Inputs
Fair Value Inputs, Liabilities, Quantitative Information
Long-term debt, fair value	711,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Liabilities, Quantitative Information
Obligations, Fair Value Disclosure	$ (5,800)