Derivative Instruments and Hedging Activities - Summary of Outstanding Interest Rate Swaps (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Interest rate swap assets	$ 2,952,000	$ 139,000
Interest rate swap liabilities	0	22,446,000
Designated as Hedging Instrument [Member] | Cash Flow Hedges [Member] | Other Assets [Member]
Derivative [Line Items]
Interest rate swap assets	2,952,000	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
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap March Two Thousand Seventeen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount, Assets	$ 1,000,000,000
Effective Dates, Assets	2015-12
Strike Rate, Assets	1.79%
Interest rate swap assets	$ 2,890,000
Aggregate notional amount	$ 400,000,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap March Two Thousand Seventeen [Member] | Cash Flow Hedges [Member] | Minimum
Derivative [Line Items]
Maturity Date, Assets	2020-12
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap March Two Thousand Seventeen [Member] | Cash Flow Hedges [Member] | Maximum
Derivative [Line Items]
Maturity Date, Assets	2022-12
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 November Two Thousand Fifteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Interest rate swap assets	$ 62,000	139,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap September Two Thousand Fifteen [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Aggregate notional amount	$ 1,000,000,000
Effective Dates, Liabilities	2015-12
Strike Rate, Liabilities	1.79%
Interest rate swap liabilities		$ 1,219,000
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap September Two Thousand Fifteen [Member] | Cash Flow Hedges [Member] | Minimum
Derivative [Line Items]
Maturity Date, Liabilities	2020-12
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap September Two Thousand Fifteen [Member] | Cash Flow Hedges [Member] | Maximum
Derivative [Line Items]
Maturity Date, Liabilities	2022-12
Designated as Hedging Instrument [Member] | 1633 Broadway [Member] | Interest Rate Swap [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Aggregate notional amount	$ 1,000,000,000