Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Real Estate [Abstract]
Land and land improvements	$ 1,094,121	$ 1,094,470
Building and improvements	4,562,908	4,501,921
Less accumulated depreciation	(995,032)	(940,115)
Operating real estate	4,661,997	4,656,276
Development in progress	410,027	267,450
Land held for development	351,933	336,569
Net real estate	5,423,957	5,260,295
Cash and cash equivalents	14,748	43,642
Restricted cash	18,115	12,383
Accounts receivable	14,509	13,994
Deferred rent receivable	120,124	109,245
Deferred financing and leasing costs, net of accumulated amortization (June 30, 2017, $161,544; December 31, 2016, $152,309)	159,112	153,393
Investments in and advances to unconsolidated joint ventures	268,346	245,078
Assets held for sale	2,731	4,548
Prepaid expenses and other assets	137,993	150,235
Total assets	6,159,635	5,992,813
LIABILITIES
Mortgage loans	271,851	276,650
Unsecured notes	2,281,650	2,280,286
Credit facility	177,000	0
Accounts payable	56,188	65,914
Accrued interest	21,718	21,878
Dividend and distributions payable	60,334	71,501
Other liabilities	222,697	206,124
Total liabilities	3,091,438	2,922,353
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of June 30, 2017 and December 31, 2016	7,537	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 147,304,661 and 146,993,018 shares issued and outstanding as of June 30, 2017 and December 31, 2016, respectively	147	147
Additional paid-in capital	3,666,703	3,655,910
Accumulated other comprehensive loss	(45,332)	(56,031)
Distributions in excess of net income	(619,929)	(596,635)
Total Liberty Property Trust shareholders' equity	3,001,589	3,003,391
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	54,170	54,631
Noncontrolling interest - consolidated joint ventures	4,901	4,901
Total owners' equity	3,060,660	3,062,923
Total liabilities, noncontrolling interest - operating partnership and equity	6,159,635	5,992,813
Liberty Property Limited Partnership [Member]
Real Estate [Abstract]
Land and land improvements	1,094,121	1,094,470
Building and improvements	4,562,908	4,501,921
Less accumulated depreciation	(995,032)	(940,115)
Operating real estate	4,661,997	4,656,276
Development in progress	410,027	267,450
Land held for development	351,933	336,569
Net real estate	5,423,957	5,260,295
Cash and cash equivalents	14,748	43,642
Restricted cash	18,115	12,383
Accounts receivable	14,509	13,994
Deferred rent receivable	120,124	109,245
Deferred financing and leasing costs, net of accumulated amortization (June 30, 2017, $161,544; December 31, 2016, $152,309)	159,112	153,393
Investments in and advances to unconsolidated joint ventures	268,346	245,078
Assets held for sale	2,731	4,548
Prepaid expenses and other assets	137,993	150,235
Total assets	6,159,635	5,992,813
LIABILITIES
Mortgage loans	271,851	276,650
Unsecured notes	2,281,650	2,280,286
Credit facility	177,000	0
Accounts payable	56,188	65,914
Accrued interest	21,718	21,878
Dividend and distributions payable	60,334	71,501
Other liabilities	222,697	206,124
Total liabilities	3,091,438	2,922,353
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of June 30, 2017 and December 31, 2016	7,537	7,537
EQUITY
General partner’s equity - 147,304,661 and 146,993,018 common units outstanding as of June 30, 2017 and December 31, 2016, respectively	3,001,589	3,003,391
Limited partners' equity	54,170	54,631
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	4,901	4,901
Total owners' equity	3,060,660	3,062,923
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,159,635	$ 5,992,813