Fair Value Disclosures (Fair Value Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Inputs, Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Insurance deposit	$ 14,347	$ 14,346
Total assets	14,347	14,346
Fair Value, Inputs, Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total assets	0	0
Derivative interest rate contracts (Note 8)	(12,263)	(6,077)
Total liabilities	$ (12,263)	$ (6,077)