Fair Value of Financial Instruments (Recurring) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financial Assets:
Cash and cash equivalents	$ 99,090	$ 104,677
Restricted cash	10,926	12,360
Equity securities	22,709	22,264
Total Financial Assets	132,725	139,301
Financial Liabilities:
Total debt	1,315,473	1,323,201
Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Cash and cash equivalents	99,090	104,677
Restricted cash	0	0
Equity securities	22,709	22,264
Total Financial Assets	121,799	126,941
Financial Liabilities:
Total debt	0	0
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Cash and cash equivalents	0	0
Restricted cash	10,926	12,360
Equity securities	0	0
Total Financial Assets	10,926	12,360
Financial Liabilities:
Total debt	1,315,473	1,323,201
Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Equity securities	0	0
Total Financial Assets	0	0
Financial Liabilities:
Total debt	0	0
Interest Rate Swap [Member]
Derivatives:
Liability for interest rate swap agreements	(4,370)	(3,781)
Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Liability for interest rate swap agreements	0	0
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Liability for interest rate swap agreements	(4,370)	(3,781)
Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Liability for interest rate swap agreements	$ 0	$ 0