Derivative and Hedging Activities (Effect of Derivative Instruments on the Consolidated Statement of Operations and Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ (5,400)
Cash Flow Hedging [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	930	$ 1,809	$ (7,564)
Cash Flow Hedging [Member] \| Other Comprehensive Income (Loss) [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Amount of gain or (loss) recognized in OCI on derivative (effective portion)	(14,968)	(1,847)	7,093
Consolidated Properties [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contract [Member] \| Other Comprehensive Income (Loss) [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Amount of gain or (loss) recognized in OCI on derivative (effective portion)	(13,239)	(2,636)	3,994
Consolidated Properties [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contract [Member] \| Interest expense [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(628)	1,133	(2,879)
Unconsolidated Properties [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contract [Member] \| Other Comprehensive Income (Loss) [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Amount of gain or (loss) recognized in OCI on derivative (effective portion)	(1,757)	943	2,898
Unconsolidated Properties [Member] \| Cash Flow Hedging [Member] \| Interest Rate Contract [Member] \| Equity Method Investments [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	355	(188)	(2,406)
Unconsolidated Properties [Member] \| Cash Flow Hedging [Member] \| Cross Currency Interest Rate Contract [Member] \| Other Comprehensive Income (Loss) [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Amount of gain or (loss) recognized in OCI on derivative (effective portion)	28	(154)	201
Unconsolidated Properties [Member] \| Cash Flow Hedging [Member] \| Cross Currency Interest Rate Contract [Member] \| Equity Method Investments [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 1,203	$ 864	$ (2,279)

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

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- Definition

The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
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- Definition

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
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