Derivative and Other Fair Value Instruments (Tables)

12 Months Ended

Dec. 31, 2012

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

Derivative Instrument Table

	Fair Value Hedges (1)			Forward Starting Swaps (2)
Current Notional Balance	$	300,000		$	200,000
Lowest Possible Notional	$	300,000		$	200,000
Highest Possible Notional	$	300,000		$	200,000
Lowest Interest Rate	2.009		%	3.478		%
Highest Interest Rate	2.637		%	4.695		%
Earliest Maturity Date	2013			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	12/31/2012		(Level 1)		(Level 2)		(Level 3)
Assets
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Fair Value Hedges	Other Assets	$	1,524	$	—	$	1,524	$	—
Supplemental Executive Retirement Plan	Other Assets	70,655		70,655		—		—
Available-for-Sale Investment Securities	Other Assets	2,214		2,214		—		—
Total		$	74,393	$	72,869	$	1,524	$	—
Liabilities
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps	Other Liabilities	$	44,050	$	—	$	44,050	$	—
Supplemental Executive Retirement Plan	Other Liabilities	70,655		70,655		—		—
Total		$	114,705	$	70,655	$	44,050	$	—
Redeemable Noncontrolling Interests –
Operating Partnership/Redeemable
Limited Partners	Mezzanine	$	398,372	$	—	$	398,372	$	—

				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	$	—

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

December 31, 2012	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
Type of Fair Value Hedge					Hedged Item
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Interest Rate Swaps	Interest expense	$	(7,448	)	Fixed rate debt	Interest expense	$	7,448
Total		$	(7,448	)			$	7,448

December 31, 2011	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
Type of Fair Value Hedge					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	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
Type of Fair Value Hedge				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	)

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

	Effective Portion							Ineffective Portion
December 31, 2012	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
Type of Cash Flow Hedge
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps/Treasury Locks	$	(11,772	)	Interest expense	$	(14,678	)	N/A	$	—
Total	$	(11,772	)		$	(14,678	)		$	—

	Effective Portion							Ineffective Portion
December 31, 2011	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
Type of Cash Flow Hedge
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	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
Type of Cash Flow Hedge
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	)		$	—

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, 2012 and 2011, respectively (amounts in thousands):

		Other Assets
December 31, 2012	Maturity	Amortized Cost		Unrealized Gains		Unrealized Losses		Book/ Fair Value		Interest and Other Income
Security
Available-for-Sale Investment Securities	N/A	$	675	$	1,539	$	—	$	2,214	$	—
Total		$	675	$	1,539	$	—	$	2,214	$	—

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