Derivative Instruments and Hedging Activities - Summary of Outstanding Interest Rate Swaps (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Interest rate swap liabilities	$ 22,446,000	$ 93,936,000
Interest rate swap assets	139,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount, Liabilities	840,000,000
Interest rate swap liabilities	21,227,000	84,695,000
Not Designated as Hedging Instrument [Member] | One Market Plaza [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount, Liabilities	$ 840,000,000
Maturity Date, Liabilities	2017-08
Strike Rate, Liabilities	5.02%
Interest rate swap liabilities	$ 21,227,000	55,404,000
Not Designated as Hedging Instrument [Member] | One Market Plaza [Member] | Minimum | Interest Rate Swap [Member]
Derivative [Line Items]
Effective Dates, Liabilities	2007-08
Not Designated as Hedging Instrument [Member] | One Market Plaza [Member] | Maximum | Interest Rate Swap [Member]
Derivative [Line Items]
Effective Dates, Liabilities	2012-08
Not Designated as Hedging Instrument [Member] | 31 West 52nd Street [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Interest rate swap liabilities		17,661,000
Not Designated as Hedging Instrument [Member] | 900 Third Avenue [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Interest rate swap liabilities		11,630,000
Designated as Hedging Instrument [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Interest rate swap assets	$ 139,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Interest rate swap liabilities	1,219,000	9,241,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount, Liabilities	1,000,000,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap November Two Thousand Fifteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount, Liabilities	$ 400,000,000
Effective Dates, Liabilities	2020-12
Maturity Date, Liabilities	2021-12
Strike Rate, Liabilities	2.35%
Interest rate swap liabilities		37,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap September Two Thousand Fifteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount, Liabilities	$ 1,000,000,000
Effective Dates, Liabilities	2015-12
Strike Rate, Liabilities	1.79%
Interest rate swap liabilities	$ 1,219,000	$ 9,204,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap December Two Thousand Sixteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount, Assets	$ 400,000,000
Effective Dates, Assets	2020-12
Maturity Date, Assets	2021-12
Strike Rate, Assets	2.35%
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap March Two Thousand Sixteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount, Liabilities	$ 400,000,000
Interest rate swap assets	$ 139,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Minimum | Interest Rate Swap September Two Thousand Fifteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Maturity Date, Liabilities	2020-12
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Maximum | Interest Rate Swap September Two Thousand Fifteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Maturity Date, Liabilities	2022-12