Unsecured Notes Payable to Current and Former Related Parties (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Feb. 06, 2014
Related Party Transaction [Line Items]
Aggregate principal amount of promissory notes payable to certain affiliates	$ 29,433,000	$ 29,433,000
Accrued interest on unsecured notes payable to related parties	15,627,000	12,776,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Aggregate principal amount of promissory notes payable to certain affiliates	29,400,000
Interest expense related to notes exchanged for shares of common stock in 2009	300,000
Accrued interest on unsecured notes payable to related parties	15,600,000	12,800,000
Operating Partnership | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Aggregate principal amount of promissory notes payable to certain affiliates	$ 29,400,000	$ 21,100,000
Interest rate on related party promissory notes	7.00%
Extension period on promissory notes payable maturity at Operating Partnership's option (in years)	1 year
Minimum amount of underwritten public offering that will trigger acceleration of maturity of related party promissory notes	$ 75,000,000
First Insurance Center | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Aggregate principal amount of promissory notes payable to certain affiliates	$ 8,300,000		$ 8,300,000
Interest rate on related party promissory notes	5.00%