Fair Value Disclosures (Fair Value Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 182	$ 381
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investment in SPG Common Shares	43,008	44,418
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Insurance deposit	15,430	15,440
Total assets	58,438	59,858
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value, Gross Asset	22
Derivative Asset
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total assets	22	0
Derivative interest rate contracts (Note 7)	(2,824)	(3,548)
Total liabilities	$ (2,824)	$ (3,548)