Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
OPERATING ACTIVITIES
Net income	$ 74,106	$ 74,656
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	57,589	45,585
Amortization of deferred financing costs	1,510	980
Equity in earnings of unconsolidated joint ventures	(4,159)	(1,757)
Distributions from unconsolidated joint ventures	0	265
Gain on property dispositions	(46,117)	(41,713)
Share-based compensation	6,580	4,445
Other	(635)	(1,612)
Changes in operating assets and liabilities:
Restricted cash	31,726	4,639
Accounts receivable	(4,052)	642
Deferred rent receivable	(2,765)	(3,246)
Prepaid expenses and other assets	(26,557)	1,319
Accounts payable	6,562	1,136
Accrued interest	16,441	18,867
Other liabilities	(36,537)	(12,002)
Net cash provided by operating activities	73,692	92,204
INVESTING ACTIVITIES
Investment in operating properties - acquisitions	(37,635)	0
Investment in operating properties - other	(16,522)	(6,794)
Investments in and advances to unconsolidated joint ventures	(429)	(6,379)
Distributions from unconsolidated joint ventures	2,978	1,871
Net proceeds from disposition of properties/land	327,160	71,909
Net proceeds from (advances on) public reimbursement receivable/escrow	5,001	8,500
Investment in development in progress	(74,478)	(27,509)
Investment in land held for development	(1,967)	(3,493)
Investment in deferred leasing costs	(9,158)	(7,387)
Net cash provided by investing activities	194,950	30,718
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	15,472	44,927
Proceeds from mortgage loans	0	3,261
Repayments of mortgage loans	(2,019)	(1,249)
Proceeds from credit facility	0	19,600
Repayments on credit facility	0	(111,600)
Increase in deferred financing costs	(3,619)	(4)
Distribution paid on common shares	(69,634)	(56,274)
Distribution paid on units	(1,914)	(1,961)
Net cash used in financing activities	(61,714)	(103,300)
Net increase in cash and cash equivalents	206,928	19,622
Increase (decrease) in cash and cash equivalents related to foreign currency translation	211	(3,544)
Cash and cash equivalents at beginning of period	163,414	38,356
Cash and cash equivalents at end of period	370,553	54,434
Liberty Property Limited Partnership [Member]
OPERATING ACTIVITIES
Net income	74,106	74,656
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	57,589	45,585
Amortization of deferred financing costs	1,510	980
Equity in earnings of unconsolidated joint ventures	(4,159)	(1,757)
Distributions from unconsolidated joint ventures	0	265
Gain on property dispositions	(46,117)	(41,713)
Share-based compensation	6,580	4,445
Other	(635)	(1,612)
Changes in operating assets and liabilities:
Restricted cash	31,726	4,639
Accounts receivable	(4,052)	642
Deferred rent receivable	(2,765)	(3,246)
Prepaid expenses and other assets	(26,557)	1,319
Accounts payable	6,562	1,136
Accrued interest	16,441	18,867
Other liabilities	(36,537)	(12,002)
Net cash provided by operating activities	73,692	92,204
INVESTING ACTIVITIES
Investment in operating properties - acquisitions	(37,635)	0
Investment in operating properties - other	(16,522)	(6,794)
Investments in and advances to unconsolidated joint ventures	(429)	(6,379)
Distributions from unconsolidated joint ventures	2,978	1,871
Net proceeds from disposition of properties/land	327,160	71,909
Net proceeds from (advances on) public reimbursement receivable/escrow	5,001	8,500
Investment in development in progress	(74,478)	(27,509)
Investment in land held for development	(1,967)	(3,493)
Investment in deferred leasing costs	(9,158)	(7,387)
Net cash provided by investing activities	194,950	30,718
FINANCING ACTIVITIES
Proceeds from mortgage loans	0	3,261
Repayments of mortgage loans	(2,019)	(1,249)
Proceeds from credit facility	0	19,600
Repayments on credit facility	0	(111,600)
Increase in deferred financing costs	(3,619)	(4)
Capital contributions	15,472	44,927
Distributions to partners	71,548	58,235
Net cash used in financing activities	(61,714)	(103,300)
Net increase in cash and cash equivalents	206,928	19,622
Increase (decrease) in cash and cash equivalents related to foreign currency translation	211	(3,544)
Cash and cash equivalents at beginning of period	163,414	38,356
Cash and cash equivalents at end of period	$ 370,553	$ 54,434