Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Real Estate [Abstract]
Land and land improvements	$ 1,009,941	$ 1,184,927
Building and improvements	4,409,422	5,131,648
Less accumulated depreciation	(917,201)	(1,148,928)
Operating real estate	4,502,162	5,167,647
Development in progress	427,686	360,948
Land held for development	325,444	336,967
Net real estate	5,255,292	5,865,562
Cash and cash equivalents	42,290	35,353
Restricted cash	5,661	9,018
Accounts receivable	13,983	14,343
Deferred rent receivable	106,864	118,787
Deferred financing and leasing costs, net of accumulated amortization (September 30, 2016, $153,022; December 31, 2015, $175,798)	153,593	192,109
Investments in and advances to unconsolidated joint ventures	236,800	218,454
Assets held for sale	786,272	4,954
Prepaid expenses and other assets	122,167	99,049
Total assets	6,722,922	6,557,629
LIABILITIES
Mortgage loans	281,384	307,908
Unsecured notes	2,675,644	2,580,108
Credit facility	420,000	259,000
Accounts payable	76,599	51,382
Accrued interest	38,954	26,154
Dividend and distributions payable	71,378	71,787
Other liabilities	204,031	243,806
Liabilities held for sale	25,416	0
Total liabilities	3,793,406	3,540,145
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2016 and December 31, 2015	7,537	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 146,981,465 and 147,577,984 shares issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	147	148
Additional paid-in capital	3,654,652	3,669,627
Accumulated other comprehensive loss	(41,459)	(17,893)
Distributions in excess of net income	(746,530)	(698,954)
Total Liberty Property Trust shareholders' equity	2,866,810	2,952,928
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	51,250	53,100
Noncontrolling interest - consolidated joint ventures	3,919	3,919
Total owners' equity	2,921,979	3,009,947
Total liabilities, noncontrolling interest - operating partnership and equity	6,722,922	6,557,629
Liberty Property Limited Partnership [Member]
Real Estate [Abstract]
Land and land improvements	1,009,941	1,184,927
Building and improvements	4,409,422	5,131,648
Less accumulated depreciation	(917,201)	(1,148,928)
Operating real estate	4,502,162	5,167,647
Development in progress	427,686	360,948
Land held for development	325,444	336,967
Net real estate	5,255,292	5,865,562
Cash and cash equivalents	42,290	35,353
Restricted cash	5,661	9,018
Accounts receivable	13,983	14,343
Deferred rent receivable	106,864	118,787
Deferred financing and leasing costs, net of accumulated amortization (September 30, 2016, $153,022; December 31, 2015, $175,798)	153,593	192,109
Investments in and advances to unconsolidated joint ventures	236,800	218,454
Assets held for sale	786,272	4,954
Prepaid expenses and other assets	122,167	99,049
Total assets	6,722,922	6,557,629
LIABILITIES
Mortgage loans	281,384	307,908
Unsecured notes	2,675,644	2,580,108
Credit facility	420,000	259,000
Accounts payable	76,599	51,382
Accrued interest	38,954	26,154
Dividend and distributions payable	71,378	71,787
Other liabilities	204,031	243,806
Liabilities held for sale	25,416	0
Total liabilities	3,793,406	3,540,145
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2016 and December 31, 2015	7,537	7,537
EQUITY
General partner’s equity - 146,981,465 and 147,577,984 common units outstanding as of September 30, 2016 and December 31, 2015, respectively	2,866,810	2,952,928
Limited partners' equity	51,250	53,100
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	3,919	3,919
Total owners' equity	2,921,979	3,009,947
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,722,922	$ 6,557,629