Debt - Summary of Outstanding Debt (Parenthetical) (Details)	3 Months Ended
	Mar. 31, 2017 USD ($)
1633 Broadway [Member] | Mortgages and Notes Payable with Variable Rate [Member]
Debt Instrument [Line Items]
Additional Borrowing Capacity Subject To Performance Hurdles	$ 250,000,000
Additional Borrowing Capacity Interest Rate Description	LIBOR plus 175 basis points
1633 Broadway [Member] | Mortgages and Notes Payable with Variable Rate [Member] | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Fixed/Variable Rate	1.75%
One Market Plaza [Member]
Debt Instrument [Line Items]
Ownership interest rate of property	49.00%