Fair Value Measurements (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) trail	Dec. 31, 2014 USD ($)	Jan. 31, 2013
Extinguishment of Debt [Line Items]
Carrying value of outstanding debt	$ 209,282	$ 209,911
Triangular distribution, number of trails | trail	500,000
Senior Subordinated 6.25% Notes
Extinguishment of Debt [Line Items]
Carrying value of outstanding debt	$ 210,000	$ 210,000
Senior Subordinated Notes, interest rate	6.25%	6.25%	6.25%