Real Estate Investments - Intangible Assets Acquired and Intangible Liabilities Assumed (Details) - Commerce Square [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2013	Dec. 19, 2013
Acquired Finite Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 85,036
Leases, Acquired-in-Place [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		80,916
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 years 10 months 24 days
Above Market Leases [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		4,120
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 10 months 24 days
Below Market Lease [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ (8,637)
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 6 months