Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
OPERATING ACTIVITIES
Net income	$ 165,854,000	$ 162,085,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	156,562,000	173,726,000
Amortization of deferred financing costs	3,068,000	3,249,000
Impairment - real estate assets	0	16,775,000
Loss on debt extinguishment	3,494,000	0
Equity in earnings of unconsolidated joint ventures	(19,540,000)	(805,000)
Distributions from unconsolidated joint ventures	0	2,490,000
Gain on property dispositions	(25,671,000)	(56,987,000)
Share-based compensation/Non-cash compensation	12,841,000	10,709,000
Other	(5,326,000)	(8,143,000)
Changes in operating assets and liabilities:
Restricted cash	4,059,000	4,914,000
Accounts receivable	(4,980,000)	1,023,000
Deferred rent receivable	(12,948,000)	(17,122,000)
Prepaid expenses and other assets	(22,172,000)	(20,182,000)
Accounts payable	21,343,000	8,312,000
Accrued interest	12,800,000	19,258,000
Other liabilities	(2,561,000)	371,000
Net cash provided by operating activities	286,823,000	299,673,000
INVESTING ACTIVITIES
Investment in properties - acquisitions	(9,278,000)	(100,756,000)
Investment in properties - other	(44,017,000)	(58,038,000)
Investments in and advances to unconsolidated joint ventures	(50,460,000)	(30,609,000)
Distributions from unconsolidated joint ventures	49,372,000	23,093,000
Net proceeds from disposition of properties/land	142,808,000	243,943,000
Investment in development in progress	(259,193,000)	(123,547,000)
Investment in land held for development	(70,809,000)	(101,934,000)
Payment of deferred leasing costs	(22,306,000)	(34,404,000)
Investing - Other	4,874,000	(6,366,000)
Net cash used in investing activities	(259,009,000)	(188,618,000)
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	11,967,000	38,195,000
Share repurchase	(40,896,000)	(65,463,000)
Proceeds from unsecured notes	396,648,000	398,576,000
Repayment of unsecured notes including prepayment premium	(303,673,000)	(300,000,000)
Repayments of mortgage loans	(25,260,000)	(112,970,000)
Proceeds from credit facility	466,300,000	919,700,000
Repayments on credit facility	(305,300,000)	(786,700,000)
Payment of deferred financing costs	(2,600,000)	(3,478,000)
Distribution paid on common shares	(209,428,000)	(212,402,000)
Distribution paid on units	(5,690,000)	(5,704,000)
Net cash used in financing activities	(17,932,000)	(130,246,000)
Net increase (decrease) in cash and cash equivalents	9,882,000	(19,191,000)
Decrease in cash and cash equivalents related to foreign currency translation	(2,945,000)	(1,503,000)
Cash and cash equivalents at beginning of period	35,353,000	69,346,000
Cash and cash equivalents at end of period	42,290,000	48,652,000
Liberty Property Limited Partnership [Member]
OPERATING ACTIVITIES
Net income	165,854,000	162,085,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	156,562,000	173,726,000
Amortization of deferred financing costs	3,068,000	3,249,000
Impairment - real estate assets	0	16,775,000
Loss on debt extinguishment	3,494,000	0
Equity in earnings of unconsolidated joint ventures	(19,540,000)	(805,000)
Distributions from unconsolidated joint ventures	0	2,490,000
Gain on property dispositions	(25,671,000)	(56,987,000)
Share-based compensation/Non-cash compensation	12,841,000	10,709,000
Other	(5,326,000)	(8,143,000)
Changes in operating assets and liabilities:
Restricted cash	4,059,000	4,914,000
Accounts receivable	(4,980,000)	1,023,000
Deferred rent receivable	(12,948,000)	(17,122,000)
Prepaid expenses and other assets	(22,172,000)	(20,182,000)
Accounts payable	21,343,000	8,312,000
Accrued interest	12,800,000	19,258,000
Other liabilities	(2,561,000)	371,000
Net cash provided by operating activities	286,823,000	299,673,000
INVESTING ACTIVITIES
Investment in properties - acquisitions	(9,278,000)	(100,756,000)
Investment in properties - other	(44,017,000)	(58,038,000)
Investments in and advances to unconsolidated joint ventures	(50,460,000)	(30,609,000)
Distributions from unconsolidated joint ventures	49,372,000	23,093,000
Net proceeds from disposition of properties/land	142,808,000	243,943,000
Investment in development in progress	(259,193,000)	(123,547,000)
Investment in land held for development	(70,809,000)	(101,934,000)
Payment of deferred leasing costs	(22,306,000)	(34,404,000)
Investing - Other	4,874,000	(6,366,000)
Net cash used in investing activities	(259,009,000)	(188,618,000)
FINANCING ACTIVITIES
Proceeds from unsecured notes	396,648,000	398,576,000
Repayment of unsecured notes including prepayment premium	(303,673,000)	(300,000,000)
Repayments of mortgage loans	(25,260,000)	(112,970,000)
Proceeds from credit facility	466,300,000	919,700,000
Repayments on credit facility	(305,300,000)	(786,700,000)
Payment of deferred financing costs	(2,600,000)	(3,478,000)
Capital contributions	11,967,000	38,195,000
Distributions to partners	(256,014,000)	(283,569,000)
Net cash used in financing activities	(17,932,000)	(130,246,000)
Net increase (decrease) in cash and cash equivalents	9,882,000	(19,191,000)
Decrease in cash and cash equivalents related to foreign currency translation	(2,945,000)	(1,503,000)
Cash and cash equivalents at beginning of period	35,353,000	69,346,000
Cash and cash equivalents at end of period	$ 42,290,000	$ 48,652,000