Investment in Unconsolidated Joint Ventures - Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($) equity_investment property	Dec. 31, 2015 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated joint ventures | equity_investment	4
Courvoisier Centre JV, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 14,100
Difference between carrying amount and underlying equity in equity investment	$ 7,700
Amortization period for the excess investment amount	39 years
Consolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of office and parking properties | property	32
Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 45,262	$ 39,592
Unconsolidated Properties | Courvoisier Centre JV, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 6,352	$ 0