Owners' Equity - Operating Partnership(Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Outstanding	0	1,290,000
Preferred Stock Redemption Discount		$ 3,689,000
Preferred Stock Redemption Premium	1,236,000
Preferred Units, Total Annual Cash Distributions	1,600,000.0	9,900,000.0	21,000,000.00
Equity Offering [Abstract]
Proceeds from Issuance of Common Stock	969,468,000	58,710,000	44,552,000
Series B Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 0.00	$ 0.45	$ 1.86
Stock Redeemed or Called During Period, Value		95,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount		7.45%
Series E Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 1.21	$ 3.50	$ 3.50
Stock Redeemed or Called During Period, Value	20,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount	7.00%
Series F Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Payments for Repurchase of Preferred Stock and Preference Stock		26,000,000
Preferred Units, Annual Cash Distributions	$ 1.32	$ 1.43	$ 3.33
Stock Redeemed or Called During Period, Value	17,500,000	32,500,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount	6.65%	6.65%
Series G Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 1.33	$ 3.35	$ 3.35
Stock Redeemed or Called During Period, Value	27,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount	6.70%
Series H Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 0.00	$ 0.77	$ 1.85
Stock Redeemed or Called During Period, Value		100,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount		7.40%
Liberty Property Limited Partnership [Member]
Limited Partners' Capital Account [Line Items]
Limited Partners' Capital Account, Units Outstanding	3,556,566	3,713,851
market value of the outstanding common units	120,500,000
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Outstanding	0	1,290,000
Preferred Stock Redemption Discount		3,689,000	0
Preferred Stock Redemption Premium	1,236,000
Preferred Units, Total Annual Cash Distributions	1,600,000	9,900,000	21,000,000
Liberty Property Limited Partnership [Member] | Series B Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 0.00	$ 0.45	$ 1.86
Stock Redeemed or Called During Period, Value		95,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount		7.45%
Liberty Property Limited Partnership [Member] | Series E Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 1.21	$ 3.50	$ 3.50
Stock Redeemed or Called During Period, Value	20,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount	7.00%
Liberty Property Limited Partnership [Member] | Series F Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Payments for Repurchase of Preferred Stock and Preference Stock		26,000,000
Preferred Units, Annual Cash Distributions	$ 1.32	$ 1.43	$ 3.33
Stock Redeemed or Called During Period, Value	17,500,000	32,500,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount	6.65%	6.65%
Liberty Property Limited Partnership [Member] | Series G Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 1.33	$ 3.35	$ 3.35
Stock Redeemed or Called During Period, Value	27,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount	6.70%
Liberty Property Limited Partnership [Member] | Series H Preferred Stock [Member]
Preferred Units Description and Other Disclosures [Abstract]
Preferred Units, Annual Cash Distributions	$ 0.00	$ 0.77	$ 1.85
Stock Redeemed or Called During Period, Value		100,000,000
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount		7.40%
Continuous Equity Offering [Member]
Equity Offering [Abstract]
Common stock, Continuous equity offering program, Max amount of equity	200,000,000
Continuous Equity Offering [Member] | Liberty Property Limited Partnership [Member]
Equity Offering [Abstract]
Common stock, Continuous equity offering program, Max amount of equity	200,000,000
Common Stock [Member] | Continuous Equity Offering [Member]
Equity Offering [Abstract]
Stock Issued During Period, Shares, New Issues	1,900,000	0	0
Proceeds from Issuance of Common Stock	75,000,000
Common Stock [Member] | Continuous Equity Offering [Member] | Liberty Property Limited Partnership [Member]
Equity Offering [Abstract]
Stock Issued During Period, Shares, New Issues	1,900,000	0	0
Proceeds from Issuance of Common Stock	$ 75,000,000