Debt Schedule of Maturities of Long-term Debt (Details) (USD $)	9 Months Ended			9 Months Ended		0 Months Ended				9 Months Ended				0 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Mortgage notes payable	Dec. 31, 2013 Mortgage notes payable	Sep. 30, 2014 1350 Broadway - 2nd Lien Mortgage Loan [Member] Mortgage notes payable	Sep. 30, 2014 Metro Center Debt [Member] Mortgage notes payable	Oct. 01, 2014 Subsequent Event [Member] 1350 Broadway - 2nd Lien Mortgage Loan [Member] Mortgage notes payable	Oct. 01, 2014 Subsequent Event [Member] Metro Center Debt [Member] Mortgage notes payable	Oct. 01, 2014 Subsequent Event [Member] Metro Center Debt [Member] Mortgage notes payable	Oct. 01, 2014 Subsequent Event [Member] One Grand Central Place - Fourth Lien [Member] Mortgage notes payable	Sep. 30, 2014 Prime Rate [Member] 1350 Broadway - 2nd Lien Mortgage Loan [Member] Mortgage notes payable		Dec. 31, 2013 Prime Rate [Member] 1350 Broadway - 2nd Lien Mortgage Loan [Member] Mortgage notes payable		Oct. 01, 2014 LIBOR [Member] Subsequent Event [Member] One Grand Central Place - Fourth Lien [Member] Mortgage notes payable
Debt Instrument [Line Items]
2014		$ 108,137,000
2015		144,989,000
2016		101,994,000
2017		419,395,000
2018		562,979,000
2019		250,000,000
Total		1,587,494,000	1,196,419,000
Repayments of Long-term Debt	57,478,000			13,700,000		13,700,000
Proceeds from credit facility	295,600,000						100,000,000
Stated Rate					5.89%			3.59%				4.25%	[1]
Payments of Debt Extinguishment Costs							2,800,000
Debt Instrument, Face Amount									$ 91,000,000
Basis spread on variable rate										1.00%	[1]			1.35%	[2]

[1] Interest at the greater of 4.25% and Prime plus 1.0%. The rate at September 30, 2014 was 4.25%.

[2] Floating at 30 day LIBOR plus 1.20%. The rate as of September 30, 2014 was 1.36%.