Derivative and Other Fair Value Instruments (Tables)

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Derivative and Other Fair Value Instruments (Tables) [Abstract]

Derivative Instrument Table

	Fair Value Hedges (1)			Forward Starting Swaps (2)
Current Notional Balance	$	315,693		$	200,000
Lowest Possible Notional	$	315,693		$	200,000
Highest Possible Notional	$	317,694		$	200,000
Lowest Interest Rate	2.009		%	3.478		%
Highest Interest Rate	4.800		%	4.695		%
Earliest Maturity Date	2012			2023
Latest Maturity Date	2013			2023

Schedule of Location and Amount of Financial Instruments on Balanace Sheet

				Fair Value Measurements at Reporting Date Using
				Quoted Prices in
				Active Markets for		Significant Other		Significant
	Balance Sheet			Identical Assets/Liabilities		Observable Inputs		Unobservable Inputs
Description	Location	12/31/2011		(Level 1)		(Level 2)		(Level 3)
Assets
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Fair Value Hedges	Other Assets	$	8,972	$	—	$	8,972	$	—
Supplemental Executive Retirement Plan	Other Assets	71,426		71,426		—		—
Available-for-Sale Investment Securities	Other Assets	1,550		1,550		—		—
Total		$	81,948	$	72,976	$	8,972	$	—
Liabilities
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps	Other Liabilities	$	32,278	$	—	$	32,278	$	—
Supplemental Executive Retirement Plan	Other Liabilities	71,426		71,426		—		—
Total		$	103,704	$	71,426	$	32,278	$	—
Redeemable Noncontrolling Interests –
Operating Partnership/Redeemable
Limited Partners	Mezzanine	$	416,404	$	—	$	416,404	$	—

				Fair Value Measurements at Reporting Date Using
				Quoted Prices in
				Active Markets for		Significant Other		Significant
	Balance Sheet			Identical Assets/Liabilities		Observable Inputs		Unobservable Inputs
Description	Location	12/31/2010		(Level 1)		(Level 2)		(Level 3)
Assets
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Fair Value Hedges	Other Assets	$	12,521	$	—	$	12,521	$	—
Forward Starting Swaps	Other Assets	3,276		—		3,276		—
Supplemental Executive Retirement Plan	Other Assets	58,132		58,132		—		—
Available-for-Sale Investment Securities	Other Assets	1,194		1,194		—		—
Total		$	75,123	$	59,326	$	15,797	$	—
Liabilities
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps	Other Liabilities	$	37,756	$	—	$	37,756	$	—
Development Cash Flow Hedges	Other Liabilities	1,322		—		1,322		—
Supplemental Executive Retirement Plan	Other Liabilities	58,132		58,132		—		—
Total		$	97,210	$	58,132	$	39,078	$	—
Redeemable Noncontrolling Interests –
Operating Partnership/Redeemable
Limited Partners	Mezzanine	383,540		—		383,540		—

Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Table Text Block]

			Fair Value Measurements at Reporting Date Using
			Quoted Prices in
			Active Markets for		Significant Other		Significant
			Identical Assets/Liabilities		Observable Inputs		Unobservable Inputs
Description	12/31/2010		(Level 1)		(Level 2)		(Level 3)		Total Gains (Losses)
Assets
Long-lived assets	$	56,000	$	—	$	—	$	56,000	$	(45,380	)
Total	$	56,000	$	—	$	—	$	56,000	$	(45,380	)

Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]

December 31, 2011 Type of Fair Value Hedge	Location of Gain/(Loss) Recognized in Income on Derivative	Amount of Gain/(Loss) Recognized in Income on Derivative				Income Statement Location of Hedged Item Gain/(Loss)	Amount of Gain/(Loss)Recognized in Income on Hedged Item
					Hedged Item
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Interest Rate Swaps	Interest expense	$	(3,549	)	Fixed rate debt	Interest expense	$	3,549
Total		$	(3,549	)			$	3,549

December 31, 2010 Type of Fair Value Hedge	Location of Gain/(Loss) Recognized in Income on Derivative	Amount of Gain/(Loss) Recognized in Income on Derivative			Income Statement Location of Hedged Item Gain/(Loss)	Amount of Gain/(Loss)Recognized in Income on Hedged Item
				Hedged Item
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Interest Rate Swaps	Interest expense	$	7,335	Fixed rate debt	Interest expense	$	(7,335	)
Total		$	7,335			$	(7,335	)

December 31, 2009 Type of Fair Value Hedge	Location of Gain/(Loss) Recognized in Income on Derivative	Amount of Gain/(Loss) Recognized in Income on Derivative				Income Statement Location of Hedged Item Gain/(Loss)	Amount of Gain/(Loss)Recognized in Income on Hedged Item
					Hedged Item
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Interest Rate Swaps	Interest expense	$	(1,167	)	Fixed rate debt	Interest expense	$	1,167
Total		$	(1,167	)			$	1,167

Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]

	Effective Portion							Ineffective Portion
December 31, 2011 Type of Cash Flow Hedge	Amount of Gain/(Loss) Recognized in OCI on Derivative			Location of Gain/(Loss) Reclassified from Accumulated OCI into Income	Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income			Location of Gain/(Loss) Recognized in Income on Derivative	Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps/Treasury Locks	$	(145,090	)	Interest expense	$	(4,343	)	Interest expense	$	(170	)
Development Interest Rate Swaps/Caps	1,322			Interest expense	—			N/A	—
Total	$	(143,768	)		$	(4,343	)		$	(170	)

	Effective Portion							Ineffective Portion
December 31, 2010 Type of Cash Flow Hedge	Amount of Gain/(Loss) Recognized in OCI on Derivative			Location of Gain/(Loss) Reclassified from Accumulated OCI into Income	Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income			Location of Gain/(Loss) Recognized in Income on Derivative	Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps/Treasury Locks	$	(68,149	)	Interest expense	$	(3,338	)	N/A	$	—
Development Interest Rate Swaps/Caps	2,255			Interest expense	—			N/A	—
Total	$	(65,894	)		$	(3,338	)		$	—

	Effective Portion						Ineffective Portion
December 31, 2009 Type of Cash Flow Hedge	Amount of Gain/(Loss) Recognized in OCI on Derivative		Location of Gain/(Loss) Reclassified from Accumulated OCI into Income	Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income			Location of Gain/(Loss) Recognized in Income on Derivative	Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps/Treasury Locks	$	34,432	Interest expense	$	(3,724	)	N/A	$	—
Development Interest Rate Swaps/Caps	3,244		Interest expense	—			N/A	—
Total	$	37,676		$	(3,724	)		$	—

Available-for-sale Securities [Table Text Block]

The following tables set forth the maturity, amortized cost, gross unrealized gains and losses, book/fair value and interest and other income of the various investment securities held as of December 31, 2011 and 2010, respectively (amounts in thousands):

		Other Assets
December 31, 2011 Security	Maturity	Amortized Cost		Unrealized Gains		Unrealized Losses		Book/ Fair Value		Interest and Other Income
Available -for-Sale Investment Securities	N/A	$	675	$	875	$	—	$	1,550	$	—
Total		$	675	$	875	$	—	$	1,550	$	—

		Other Assets
December 31, 2010 Security	Maturity	Amortized Cost		Unrealized Gains		Unrealized Losses		Book/ Fair Value		Interest and Other Income
Available-for-Sale
FDIC-insured certificates of deposit	Less than one year	$	—	$	—	$	—	$	—	$	61
Other	N/A	675		519		—		1,194		—
Total Available-for-Sale and Grand Total		$	675	$	519	$	—	$	1,194	$	61