Noncontrolling Interests Noncontrolling Interests Textual (Details) - Jun. 30, 2015	USD ($) a ft²
Bristol Development Group [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest cash contribution	$ 350,000
7001 Arlington at Bethesda [Member]
Noncontrolling Interest [Line Items]
Equity interest	98.10%
Area of land | a	2.5
Contribution	$ 12,200,000
Real estate units intended to develop	140
Square feet of space | ft²	6,898