Secured and Unsecured Debt of the Operating Partnership (Tables)

6 Months Ended

Jun. 30, 2011

Secured and Unsecured Debt of the Operating Partnership [Abstract]

Balance and significant terms of the exchangeable notes outstanding

	3.25% Exchangeable Notes						4.25% Exchangeable Notes
	June 30,			December 31,			June 30,			December 31,
	2011			2010			2011			2010
	(in thousands)
Principal amount	$	148,000		$	148,000		$	172,500		$	172,500
Unamortized discount		(2,485	)		(4,004	)		(14,641	)		(16,532	)
Net carrying amount of liability component	$	145,515		$	143,996		$	157,859		$	155,968
Carrying amount of equity component	$33,675						$19,835
Maturity date	April 2012						November 2014
Stated coupon rate	3.25%(1)						4.25%(2)
Effective interest rate(3)	5.45%						7.13%
Exchange rate per $1,000 principal value of the Exchangeable Notes, as adjusted(4)	11.3636						27.8307
Exchange price, as adjusted(4)	$88.00						$35.93
Number of shares on which the aggregate consideration to be delivered on conversion is determined(4)	1,681,813						4,800,796

(1)	Interest on the 3.25% Exchangeable Notes is payable semi-annually in arrears on April 15th and October 15th of each year.
(2)	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
(3)	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
(4)	The exchange rate, exchange price, and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.

Capped call Transactions

	3.25% Exchangeable Notes(1)		4.25% Exchangeable Notes(2)
Referenced shares of common stock		1,121,201		4,800,796
Exchange price including effect of capped calls		$102.72		$42.81

(1)	The capped calls mitigate the dilutive impact to us of the potential exchange of two-thirds of the 3.25% Exchangeable Notes into shares of common stock.
(2)	The capped calls mitigate the dilutive impact to us of the potential exchange of all of the 4.25% Exchangeable Notes into shares of common stock.

Per share average trading price of Company's common stock on New York Stock Exchange

	Three Months Ended		Six Months Ended
	June 30, 2011		June 30, 2011
Average Trading Price of the Company’s Stock	$	39.90	$	38.94

Interest expense for the exchangeable notes

	Three Months Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
	(in thousands)
Contractual interest payments	$	3,035	$	4,241	$	6,070	$	8,495
Amortization of discount		1,722		2,372		3,410		4,679
Interest expense attributable to the Exchangeable Notes	$	4,757	$	6,613	$	9,480	$	13,174

Terms of the Credit Facility

	June 30,		December 31,
	2011		2010
	(in thousands)
Outstanding borrowings	$	245,000	$	159,000
Remaining borrowing capacity		255,000		341,000
Total borrowing capacity(1)	$	500,000	$	500,000
Interest rate(2)		2.87%		2.99%
Facility fee-annual rate(3)		0.350%		0.575%
Maturity date(4)		August 2015		August 2013

(1)	We may elect to borrow, subject to lender approval, up to an additional $200 million under an accordion feature under the terms of the Credit Facility.
(2)	The Credit Facility interest rate included interest at an annual rate of LIBOR plus 1.750% and 2.675% as of June 30, 2011 and December 31, 2010, respectively.
(3)	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we also incurred debt origination and legal costs of approximately $5.0 million when we entered into the Credit Facility in 2010 and an additional $3.3 million when we amended the Credit Facility in 2011. The unamortized balance of these costs will be amortized as additional interest expense over the extended term of the Credit Facility.
(4)	Under the terms of the Credit Facility, we may exercise an option to extend the maturity date by one year.

Stated debt maturities and scheduled amortization payments, excluding debt discounts

Year Ending	(in thousands)
Remaining 2011	$	72,262
2012		305,303
2013		6,373
2014		262,443
2015		602,382
Thereafter		450,028
Total	$	1,698,791	(1)

(1) Includes gross principal balance of outstanding debt before impact of all debt discounts and premiums.

Capitalized interest and loan fees

	Three Months Ended June 30,						Six Months Ended June 30,
	2011			2010			2011			2010
	(in thousands)
Gross interest expense	$	23,293		$	15,897		$	46,148		$	30,437
Capitalized interest		(2,065	)		(2,809	)		(4,044	)		(5,393	)
Interest expense	$	21,228		$	13,088		$	42,104		$	25,044