Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
OPERATING ACTIVITIES
Net income	$ 59,063,000	$ 31,862,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	54,837,000	59,431,000
Amortization of deferred financing costs	1,002,000	1,073,000
Impairment - real estate assets	0	15,739,000
Equity in earnings of unconsolidated joint ventures	(4,914,000)	(6,906,000)
Distributions from unconsolidated joint ventures	314,000	0
Gain on property dispositions	(20,521,000)	(2,271,000)
Share-based compensation/Non-cash compensation	10,536,000	7,437,000
Other	(1,652,000)	(2,990,000)
Changes in operating assets and liabilities:
Restricted cash	2,216,000	489,000
Accounts receivable	(4,030,000)	(3,670,000)
Deferred rent receivable	(5,225,000)	(5,504,000)
Prepaid expenses and other assets	(2,926,000)	(13,058,000)
Accounts payable	3,762,000	(116,000)
Accrued interest	16,976,000	12,178,000
Other liabilities	(12,627,000)	(3,718,000)
Net cash provided by operating activities	96,811,000	89,976,000
INVESTING ACTIVITIES
Investment in properties - acquisitions	(8,000,000)	0
Investment in properties - other	(13,314,000)	(12,805,000)
Investments in and advances to unconsolidated joint ventures	(14,635,000)	(5,822,000)
Distributions from unconsolidated joint ventures	26,684,000	6,098,000
Net proceeds from disposition of properties/land	127,727,000	40,998,000
Investment in development in progress	(76,522,000)	(48,001,000)
Investment in land held for development	(15,392,000)	(4,045,000)
Payment of deferred leasing costs	(8,200,000)	(9,684,000)
Investing - Other	8,095,000	(1,601,000)
Net cash provided by (used in) investing activities	26,443,000	(34,862,000)
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	504,000	12,579,000
Share repurchase	40,896,000	0
Proceeds from unsecured notes	0	398,576,000
Repayment of unsecured notes	0	(300,000,000)
Repayments of mortgage loans	(3,101,000)	(2,160,000)
Proceeds from credit facility	187,000,000	390,000,000
Repayments on credit facility	(186,000,000)	(507,000,000)
Payment of deferred financing costs	0	(3,551,000)
Distribution paid on common shares	(70,104,000)	(70,562,000)
Distribution paid on units	(1,794,000)	(1,863,000)
Net cash used in financing activities	(114,391,000)	(83,981,000)
Net increase (decrease) in cash and cash equivalents	8,863,000	(28,867,000)
Decrease in cash and cash equivalents related to foreign currency translation	(553,000)	(1,724,000)
Cash and cash equivalents at beginning of period	35,353,000	69,346,000
Cash and cash equivalents at end of period	43,663,000	38,755,000
Liberty Property Limited Partnership [Member]
OPERATING ACTIVITIES
Net income	59,063,000	31,862,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	54,837,000	59,431,000
Amortization of deferred financing costs	1,002,000	1,073,000
Impairment - real estate assets	0	15,739,000
Equity in earnings of unconsolidated joint ventures	(4,914,000)	(6,906,000)
Distributions from unconsolidated joint ventures	314,000	0
Gain on property dispositions	(20,521,000)	(2,271,000)
Share-based compensation/Non-cash compensation	10,536,000	7,437,000
Other	(1,652,000)	(2,990,000)
Changes in operating assets and liabilities:
Restricted cash	2,216,000	489,000
Accounts receivable	(4,030,000)	(3,670,000)
Deferred rent receivable	(5,225,000)	(5,504,000)
Prepaid expenses and other assets	(2,926,000)	(13,058,000)
Accounts payable	3,762,000	(116,000)
Accrued interest	16,976,000	12,178,000
Other liabilities	(12,627,000)	(3,718,000)
Net cash provided by operating activities	96,811,000	89,976,000
INVESTING ACTIVITIES
Investment in properties - acquisitions	(8,000,000)	0
Investment in properties - other	(13,314,000)	(12,805,000)
Investments in and advances to unconsolidated joint ventures	(14,635,000)	(5,822,000)
Distributions from unconsolidated joint ventures	26,684,000	6,098,000
Net proceeds from disposition of properties/land	127,727,000	40,998,000
Investment in development in progress	(76,522,000)	(48,001,000)
Investment in land held for development	(15,392,000)	(4,045,000)
Payment of deferred leasing costs	(8,200,000)	(9,684,000)
Investing - Other	8,095,000	(1,601,000)
Net cash provided by (used in) investing activities	26,443,000	(34,862,000)
FINANCING ACTIVITIES
Proceeds from unsecured notes	0	398,576,000
Repayment of unsecured notes	0	(300,000,000)
Repayments of mortgage loans	(3,101,000)	(2,160,000)
Proceeds from credit facility	187,000,000	390,000,000
Repayments on credit facility	(186,000,000)	(507,000,000)
Payment of deferred financing costs	0	(3,551,000)
Capital contributions	504,000	12,579,000
Distributions to partners	(112,794,000)	(72,425,000)
Net cash used in financing activities	(114,391,000)	(83,981,000)
Net increase (decrease) in cash and cash equivalents	8,863,000	(28,867,000)
Decrease in cash and cash equivalents related to foreign currency translation	(553,000)	(1,724,000)
Cash and cash equivalents at beginning of period	35,353,000	69,346,000
Cash and cash equivalents at end of period	$ 43,663,000	$ 38,755,000