Owners' Equity - Operating Partnership (Liberty Property Limited Partnership [Member])

12 Months Ended

Dec. 31, 2011

Liberty Property Limited Partnership [Member]

Class of Stock [Line Items]

Partners' Capital Notes Disclosure [Text Block]

EQUITY - OPERATING PARTNERSHIP

Common units

General and limited partners' equity - common units relates to limited partnership interests of the Operating Partnership issued in connection with the formation of the Operating Partnership and certain subsequent acquisitions. The common units outstanding as of December 31, 2011 have the same economic characteristics as common shares of the Trust. The 3,808,746 outstanding common units are the limited partners' equity - common units held by persons and entities other than the Trust, the general partner of the Operating Partnership, which holds a number of common units equal to the number of outstanding common shares of beneficial interest. Both the common units held by the Trust and the common units held by persons and entities other than the Trust are counted in the weighted average number of common units outstanding during any given period. The 3,808,746 outstanding common units share proportionately in the net income or loss and in any distributions of the Operating Partnership and are exchangeable into the same number of common shares of the Trust. The market value of the 3,808,746 outstanding common units at December 31, 2011 based on the closing price of the common shares of the Company at December 31, 2011 was $117.6 million.

Preferred units

The following are the Equity Preferred Units of the Operating Partnership:

ISSUE	AMOUNT		UNITS	LIQUIDATION PREFERENCE		DIVIDEND RATE		REDEEMABLE AS OF	EXCHANGEABLE AFTER
	(in 000's)
Series B	$	95,000	3,800		$25	7.45	%	8/31/2009	8/31/13 into Series B Cumulative Redeemable Preferred Shares of the Trust
Series E	$	20,000	400		$50	7.00	%	6/16/2010	6/16/15 into Series E Cumulative Redeemable Preferred Shares of the Trust
Series F	$	50,000	1,000		$50	6.65	%	6/30/2010	12/12/15 into Series F Cumulative Redeemable Preferred Shares of the Trust
Series G	$	27,000	540		$50	6.70	%	12/15/2011	12/15/16 into Series G Cumulative Redeemable Preferred Shares of the Trust
Series H	$	100,000	4,000		$25	7.40	%	8/21/2012	8/21/17 into Series H Cumulative Redeemable Preferred Shares of the Trust

The Equity Preferred Units are callable at the Operating Partnership's option after a stated period of time. The Trust as the sole general partner of the Operating Partnership may at its option elect to settle the redemption for cash or through the exchange on a one-for-one basis with unregistered preferred shares of the Trust.

The Operating Partnership paid the following Equity Preferred Unit distributions for the years ended December 31:

	2011	2010	2009
Distributions (in millions)	$21.0	$21.0	$21.0
Distribution per unit:
Series B	$1.86	$1.86	$1.86
Series E	$3.50	$3.50	$3.50
Series F	$3.33	$3.33	$3.33
Series G	$3.35	$3.35	$3.35
Series H	$1.85	$1.85	$1.85

Continuous Equity Offering

During the year ended December 31, 2009, the Operating Partnership sold 12.8 million common units pursuant to a continuous offering program. The net proceeds from the offering of $283.2 million were used for general corporate purposes, including the funding of maturing senior note obligations. The Operating Partnership did not sell any common units pursuant to a continuous offering program during 2011 or 2010.

Noncontrolling Interest - Consolidated Joint Ventures

Noncontrolling interest - consolidated joint ventures includes third-party ownership interests in consolidated joint venture investments.