Debt (Refinanced or Issued Instruments) (Details) (USD $)	Jun. 02, 2014	Nov. 14, 2014		Dec. 15, 2014
Brook 35
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 11,500,000
Interest rate	4.65%
4.50% notes
Debt Instrument [Line Items]
Principal balance		250,000,000	[1]
Interest rate		4.50%
THE AVENUE at White Marsh
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 52,700,000	[1]
Interest rate				3.35%

[1] The net proceeds from this note offering after issuance discounts, underwriting fees and other costs were approximately $244.6 million.