Derivative and Hedging Activities (Location and Fair Value of Derivative Instruments as Reported in the Consoiidated Balance Sheet) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Location and fair value of derivative instruments as reported in the Consolidated Balance Sheet [Abstract]
Total assets designated as hedging instruments	$ 0	$ 4,875
Total liability derivatives designated as hedging instruments	(15,922)	(6,673)
Default Option, Range, Minimum [Member]
Contingent features [Abstract]
Interest Rate Recourse Provisions	100
Default Option, Range, Maximum [Member]
Contingent features [Abstract]
Interest Rate Recourse Provisions	50,000
Consolidated Properties [Member] | Interest Rate Contract [Member] | Deferred Charges And Other Assets [Member]
Location and fair value of derivative instruments as reported in the Consolidated Balance Sheet [Abstract]
Total assets designated as hedging instruments		3,530
Consolidated Properties [Member] | Interest Rate Contract [Member] | Accounts Payable and Accrued Liabilities [Member]
Location and fair value of derivative instruments as reported in the Consolidated Balance Sheet [Abstract]
Total liability derivatives designated as hedging instruments	(15,419)	(5,710)
Unconsolidated Properties [Member] | Interest Rate Contract [Member] | Equity Method Investments [Member]
Location and fair value of derivative instruments as reported in the Consolidated Balance Sheet [Abstract]
Total assets designated as hedging instruments		1,345
Total liability derivatives designated as hedging instruments	(412)
Unconsolidated Properties [Member] | Cross Currency Interest Rate Contract [Member] | Equity Method Investments [Member]
Location and fair value of derivative instruments as reported in the Consolidated Balance Sheet [Abstract]
Total liability derivatives designated as hedging instruments	$ (91)	$ (963)