v2.4.0.6

Mortgage Notes Payable (Narrative) (Details) (USD $)	3 Months Ended		0 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 12, 2012 Bay Colony Corporate Center [Member]	Mar. 31, 2012 Bay Colony Corporate Center [Member]	Mar. 31, 2012 Montvale Center [Member]
Mortgage Notes Payable [Line Items]
Debt default, accrued interest rate					9.93%
Amount of debt extinguished					$ 25,000,000
Interest at a fixed rate			6.53%
Maturity date				Jun. 11, 2012	Jun. 06, 2012
Discontinued operations gain	17,807,000				17,807,000
Repayments of mortgage notes payable	150,519,000	8,777,000	143,900,000
Penalty for early repayment of debt			0
Gains from early extinguishments of debt	$ 767,000		$ 900,000

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- Definition

Interest rate stated in the contractual debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

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Gain (loss) after tax expense or benefit, not previously recognized and resulting from the sale of a business component, which is recognized at the date of sale. A gain (loss) reflects the amount by which the consideration received exceeds (is exceeded by) the net carrying amount (reflecting previous provisions for loss on disposal, if any) of the disposal group.

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Gross amount of debt extinguished.

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The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

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