Fair Value Disclosures (Fair Value Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Investment in Simon common shares (Note 17)		$ 48,738
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative interest rate contracts (Note 10)	0	4,875
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Investment in Simon common shares (Note 17)		48,738
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Insurance deposit	11,213	10,121
Assets, Fair Value Disclosure	11,213	58,859
Fair Value, Inputs, Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Derivative interest rate contracts (Note 10)		3,530
Assets, Fair Value Disclosure	0	3,530
Derivative interest rate contract (Note 10)	(15,419)	(5,710)
Total liabilities	$ (15,419)	$ (5,710)