Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Preferred OP Units - Additional Information (Details) - $ / shares	3 Months Ended	6 Months Ended		12 Months Ended			54 Months Ended	258 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2016	Dec. 31, 1999	Jun. 30, 2020	Jun. 30, 2020
Class Of Stock [Line Items]
Denominator for Series A Preferred OP Unit conversion		$ 7.50					$ 7.50	$ 7.50
Common Shares
Class Of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)	1,697,000		2,667,000
Gotham Plaza | Common Shares
Class Of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)					442,478
Preferred quarterly distribution per share price					$ 0.9375
Number of convertible units if share price below $28.80 (in shares)					3.4722
Number of convertible units if share price above $35.20 (in shares)					2.8409
Operating Partnership, as General Partner or Managing Member
Class Of Stock [Line Items]
Series A Preferred OP Units (in shares)	3,320,325	3,101,958	3,320,325				3,101,958	3,101,958
Preferred OP Units
Class Of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)		0		0
Preferred OP Units | Gotham Plaza
Class Of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)					141,593
Share price (in dollars per share)					$ 100.00
Preferred OP Units | Gotham Plaza | Minimum
Class Of Stock [Line Items]
Share price at conversion date					28.80
Preferred OP Units | Gotham Plaza | Maximum
Class Of Stock [Line Items]
Share price at conversion date					$ 35.20
Series A Preferred Stock
Class Of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)						1,580
Preferred stock, stated value per unit		$ 1,000					$ 1,000	$ 1,000
Per unit conversion amount, Series A Preferred OP Units (in dollars per unit)		$ 22.50					$ 22.50	$ 22.50
Per unit conversion annual rate, Preferred OP Units		9.00%					9.00%	9.00%
Number of preferred OP Units converted (in shares)								1,392
Units converted from Preferred OP Units (in shares)								185,600
Series A Preferred Stock | Operating Partnership, as General Partner or Managing Member
Class Of Stock [Line Items]
Series A Preferred OP Units (in shares)	188	188	188				188	188
Series C Preferred Stock | Gotham Plaza
Class Of Stock [Line Items]
Number of preferred OP Units converted (in shares)							15,000
Units converted from Preferred OP Units (in shares)							51,887
Series C Preferred Stock | Operating Partnership, as General Partner or Managing Member
Class Of Stock [Line Items]
Series A Preferred OP Units (in shares)	136,593	126,593	136,593				126,593	126,593