Interest and Other (Loss) Income, net - Schedule Of Interest And Other (Loss) Income, net (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Preferred equity ownership percentage	24.40%		24.40%
PGRESS Equity Holdings L.P. [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Preferred equity ownership percentage	24.40%		24.40%
Preferred equity investment income, attributable to parent	$ 243	$ 355	$ 819	$ 1,047
2 Herald Square [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Preferred equity ownership percentage	24.40%		24.40%
2 Herald Square [Member] | PGRESS Equity Holdings L.P. [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Valuation allowance on preferred equity investment, attributable to parent			$ 4,780
Valuation allowance on preferred equity investment attributable to noncontrolling interests			$ 14,808
Preferred equity ownership percentage	24.40%		24.40%