Income per Common Unit of the Operating Partnership Unit Repurchase (Details) - Liberty Property Limited Partnership [Member] - 2017 Share Repurchase Program [Member] - Common Units [Member] $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) shares
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount | $	$ 250
Stock Repurchased During Period, Shares | shares	0