Summary of Significant Accounting Policies (Adjustment of Previously Reported Financial Information, Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities	$ 206,124	$ 223,499
Total liabilities	2,922,353	3,519,838
Accumulated other comprehensive loss	(56,031)	(22,506)
Distributions in excess of net income	(596,635)	(674,688)
Total Liberty Property Trust shareholders' equity	3,003,391	2,972,581
Noncontrolling interest - operating partnership	54,631	53,754
Total equity	3,062,923	3,030,254	$ 3,106,312	$ 3,117,062	[1]
Liberty Property Limited Partnership [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities	206,124	223,499
Total liabilities	2,922,353	3,519,838
Total equity	3,062,923	3,030,254	$ 3,106,312	3,117,062	[2]
General Partner's equity	3,003,391	2,972,581
Limited partners' equity	$ 54,631	53,754
Restatement of Net Profit (Loss) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities		223,499
Total liabilities		3,519,838
Accumulated other comprehensive loss		(22,506)		7,437
Distributions in excess of net income		(674,688)		(569,193)
Total Liberty Property Trust shareholders' equity		2,972,581		3,056,059
Noncontrolling interest - operating partnership		53,754		57,381
Total equity		3,030,254		3,117,062
Restatement of Net Profit (Loss) [Member] | Liberty Property Limited Partnership [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities		223,499
Total liabilities		3,519,838
Total equity		3,030,254		3,117,062
General Partner's equity		2,972,581		3,056,059
Limited partners' equity		53,754		57,381
Previously Reported [Member] | Restatement of Net Profit (Loss) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities		243,806
Total liabilities		3,540,145
Accumulated other comprehensive loss		(17,893)		9,742
Distributions in excess of net income		(698,954)		(591,713)
Total Liberty Property Trust shareholders' equity		2,952,928		3,035,844
Noncontrolling interest - operating partnership		53,100		56,713
Total equity		3,009,947		3,096,179
Previously Reported [Member] | Restatement of Net Profit (Loss) [Member] | Liberty Property Limited Partnership [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities		243,806
Total liabilities		3,540,145
Total equity		3,009,947		3,096,179
General Partner's equity		2,952,928		3,035,844
Limited partners' equity		53,100		56,713
Adjustment [Member] | Restatement of Net Profit (Loss) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities		(20,307)
Total liabilities		(20,307)
Accumulated other comprehensive loss		(4,613)		(2,305)
Distributions in excess of net income		24,266		22,520
Total Liberty Property Trust shareholders' equity		19,653		20,215
Noncontrolling interest - operating partnership		654		668
Total equity		20,307		20,883
Adjustment [Member] | Restatement of Net Profit (Loss) [Member] | Liberty Property Limited Partnership [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other liabilities		(20,307)
Total liabilities		(20,307)
Total equity		20,307		20,883
General Partner's equity		19,653		20,215
Limited partners' equity		$ 654		$ 668

[1] The Company adjusted the January 1, 2014 balances of Accumulated Other Comprehensive (Loss) Income, Distributions in Excess of Net Income, and Noncontrolling Interest - Operating Partnership - Common from previous filings. See Note 2.

[2] The Company adjusted the January 1, 2014 balances of General Partner's Equity and Limited Partners' Equity - Common Units from previous filings. See Note 2.