Investment in Unconsolidated Joint Venture - Condensed Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Oct. 30, 2013
Schedule of Equity Method Investments [Line Items]
Real estate assets, at cost	$ 1,873,531	$ 1,542,805
Less accumulated depreciation and amortization	(102,191)	(41,183)
Total real estate investments, net	1,771,340	1,501,622
Total assets	2,128,763	2,048,305
Debt	427,900
Total liabilities	921,659	599,046
Deficit	(209,463)	(86,008)
Total liabilities and equity	2,128,763	2,048,305
Worldwide Plaza
Schedule of Equity Method Investments [Line Items]
Real estate assets, at cost	698,939	696,342
Less accumulated depreciation and amortization	(92,066)	(77,919)
Total real estate investments, net	606,873	618,423
Other assets	263,068	248,048
Total assets	869,941	866,471
Debt	875,000	875,000	875,000
Other liabilities	16,772	9,923
Total liabilities	891,772	884,923
Deficit	(21,831)	(18,452)
Total liabilities and equity	869,941	866,471
Company's basis	$ 228,749	$ 234,774