Derivative and Hedging Activities (Effect of Derivative Instruments on the Consolidated Statement of Operations and Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative instruments, gain (loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 9,700,000		$ 9,700,000
Cash Flow Hedging [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	4,958,000	(396,000)	(3,035,000)	10,414,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(2,599,000)	(1,589,000)	(14,073,000)	(4,703,000)
Realized losses on settled cash flow hedges	0	(151,000)	0	(454,000)
Cash Flow Hedging [Member] | Interest rate contracts – consolidated subsidiaries | Other comprehensive income [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	3,692,000	(67,000)	(4,043,000)	6,375,000
Cash Flow Hedging [Member] | Interest rate contracts – consolidated subsidiaries | 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	(1,810,000)	(812,000)	(6,853,000)	(2,406,000)
Realized losses on settled cash flow hedges		(151,000)		(454,000)
Cash Flow Hedging [Member] | Interest rate contracts - UJVs [Member] | Other comprehensive income [Member]
Effect of derivative instruments on the Consolidated Statement of Operations and Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	1,266,000	(329,000)	1,008,000	4,039,000
Cash Flow Hedging [Member] | Interest rate contracts - UJVs [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	(789,000)	(777,000)	(2,340,000)	(2,297,000)
Consolidated Subsidiaries Interest Rate Swap1 - Non-Designated Derivative [Member]
Derivative instruments, gain (loss) [Line Items]
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net			4,900,000
Consolidated Subsidiaries Interest Rate Swap1 - Non-Designated Derivative [Member] | Cash Flow Hedging [Member] | Nonoperating Income (Expense) [Member]
Derivative instruments, gain (loss) [Line Items]
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net			$ (4,880,000)