Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
ASSETS
Land and land improvements	$ 1,139,455,000	$ 845,958,000
Building and improvements	5,144,758,000	4,045,385,000
Less accumulated depreciation	(1,057,680,000)	(1,072,859,000)
Operating real estate	5,226,533,000	3,818,484,000
Development in progress	209,187,000	248,602,000
Land held for development	233,055,000	249,221,000
Net real estate	5,668,775,000	4,316,307,000
Cash and cash equivalents	163,414,000	38,356,000
Restricted cash	51,456,000	33,147,000
Accounts receivable	13,900,000	8,988,000
Deferred rent receivable	99,956,000	101,621,000
Deferred financing and leasing costs, net	226,607,000	129,329,000
Investments in and advances to unconsolidated joint ventures	179,655,000	169,021,000
Assets held for sale	275,957,000	289,654,000
Prepaid expenses and other assets	95,840,000	87,756,000
Total assets	6,775,560,000	5,174,179,000
LIABILITIES
Mortgage Loans	545,306,000	302,855,000
Unsecured notes	2,708,213,000	2,258,751,000
Credit facility	0	92,000,000
Accounts payable	70,406,000	31,058,000
Accrued interest	25,777,000	20,164,000
Dividend and distributions payable	71,323,000	58,038,000
Other liabilities	250,819,000	185,956,000
Total liabilities	3,671,844,000	2,948,822,000
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of December 31, 2013 and December 31, 2012	7,537,000	7,537,000
EQUITY
Common shares of beneficial interest, $.001 par value, 183,987,000 shares authorized; 147,846,801 (includes 1,249,909 in treasury) and 119,720,776 (includes 1,249,909 in treasury) shares issued and outstanding as of December 31, 2013 and December 31, 2012, respectively	148,000	119,000
Additional paid-in capital	3,669,618,000	2,687,701,000
Accumulated other comprehensive income (loss)	9,742,000	2,900,000
Distributions in excess of net income	(591,713,000)	(547,757,000)
Common shares in treasury, at cost, 1,249,909 shares as of December 31, 2013 and 2012	(51,951,000)	(51,951,000)
Total Liberty Property Trust shareholders' equity	3,035,844,000	2,091,012,000
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	3,622,000	3,321,000
Total equity	3,096,179,000	2,217,820,000
Total liabilities, noncontrolling interest - operating partnership and equity	6,775,560,000	5,174,179,000
Limited Partner's Common Units [Member]
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	56,713,000	60,223,000
Limited Partner's Preferred Units [Member]
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	0	63,264,000
Liberty Property Limited Partnership [Member]
ASSETS
Land and land improvements	1,139,455,000	845,958,000
Building and improvements	5,144,758,000	4,045,385,000
Less accumulated depreciation	(1,057,680,000)	(1,072,859,000)
Operating real estate	5,226,533,000	3,818,484,000
Development in progress	209,187,000	248,602,000
Land held for development	233,055,000	249,221,000
Net real estate	5,668,775,000	4,316,307,000
Cash and cash equivalents	163,414,000	38,356,000
Restricted cash	51,456,000	33,147,000
Accounts receivable	13,900,000	8,988,000
Deferred rent receivable	99,956,000	101,621,000
Deferred financing and leasing costs, net	226,607,000	129,329,000
Investments in and advances to unconsolidated joint ventures	179,655,000	169,021,000
Assets held for sale	275,957,000	289,654,000
Prepaid expenses and other assets	95,840,000	87,756,000
Total assets	6,775,560,000	5,174,179,000
LIABILITIES
Mortgage Loans	545,306,000	302,855,000
Unsecured notes	2,708,213,000	2,258,751,000
Credit facility	0	92,000,000
Accounts payable	70,406,000	31,058,000
Accrued interest	25,777,000	20,164,000
Dividend and distributions payable	71,323,000	58,038,000
Other liabilities	250,819,000	185,956,000
Total liabilities	3,671,844,000	2,948,822,000
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of December 31, 2013 and December 31, 2012	7,537,000	7,537,000
EQUITY
General partner’s equity	3,035,844,000	2,091,012,000
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	3,622,000	3,321,000
Total equity	3,096,179,000	2,217,820,000
Total liabilities, noncontrolling interest - operating partnership and equity	6,775,560,000	5,174,179,000
Liberty Property Limited Partnership [Member] | Limited Partner's Common Units [Member]
EQUITY
Limited partners’ equity	56,713,000	60,223,000
Liberty Property Limited Partnership [Member] | Limited Partner's Preferred Units [Member]
EQUITY
Limited partners’ equity	$ 0	$ 63,264,000