Management Contracts (Details) (USD $)	3 Months Ended		3 Months Ended
	Mar. 31, 2014 Management contracts	Dec. 31, 2012 Management contracts	Mar. 31, 2014 Thomas Properties Group, Inc Contract-Based Intangible Assets	Dec. 19, 2013 Thomas Properties Group, Inc Contract-Based Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of management contracts		$ 19,000,000		$ 1,900,000
Amortization expense	1,800,000		189,000
Management contracts, net of accumulated amortization	$ 10,100,000		$ 1,700,000