Equity - Additional Information (Details)											3 Months Ended		12 Months Ended
	Dec. 07, 2021 USD ($)	Feb. 09, 2021 $ / shares	Jan. 15, 2021 USD ($)	Oct. 01, 2020 shares	Aug. 20, 2020 USD ($) $ / shares shares	Jul. 01, 2020 shares	Mar. 10, 2020 USD ($)	Aug. 06, 2019 USD ($)	Aug. 05, 2019 USD ($)	Jun. 18, 2019 USD ($) ft² $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Mar. 31, 2020 $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares	Oct. 30, 2020	Jun. 30, 2020
Class of Stock [Line Items]
Authorized capital shares of common stock (in shares)											500,000,000		500,000,000	500,000,000
Preferred stock, shares authorized (in shares)											100,000,000		100,000,000	100,000,000
Common stock, shares issued (in shares)											59,073,220		59,073,220	56,277,971
Common stock, shares outstanding (in shares)											59,073,220		59,073,220	56,277,971
Proceeds from issuance of common stock, net | $													$ 19,650,000	$ 96,845,000	$ 65,244,000
Percentage of operating partnerships held											73.90%		73.90%	72.60%
Operating partnership units redemption ratio													1
Aggregate cash dividends and distributions, paid | $													$ 47,603,000	$ 61,504,000	$ 50,897,000
Percent of total voting power for voting stock													0.50
Preferred stock, par or stated value (in dollars per share) | $ / shares											$ 0.01		$ 0.01	$ 0.01
Dividend declared (in dollars per share) | $ / shares													$ 0.44	$ 0.84	$ 0.80
Dividends, cash paid | $													$ 7,349,000	$ 2,455,000
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Granted (in shares)											10,842	10,600
Granted (in dollars per share) | $ / shares											$ 11.11	$ 18.08
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period											3,165	3,677
Subsequent Event
Class of Stock [Line Items]
Dividend declared (in dollars per share) | $ / shares		$ 0.15
Increase from prior dividend		36.00%
Class A units
Class of Stock [Line Items]
Units not held by company											20,865,485		20,865,485
Class A units | Subsequent Event
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $	$ 2,300,000
Class A units | Operating Partnership
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $													$ 9,200,000	16,900,000	$ 13,800,000
Common stock
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $													$ 25,300,000	45,400,000	$ 38,700,000
Common stock | Subsequent Event
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $	$ 6,500,000
2018 ATM Program | Common stock
Class of Stock [Line Items]
Maximum aggregate offering price of shares to be sold (up to) | $								$ 180,700,000	$ 125,000,000.0
The Amendments, At-the-Market Continuous Equity Program [Member] | Common stock
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues													1,783,768
Sale of stock, weighted average price per share | $ / shares													$ 10.48
The Amendments, At-the-Market Continuous Equity Program [Member] | Preferred stock
Class of Stock [Line Items]
Net proceeds after offering costs and commissions from sale of shares | $													$ 18,400,000
Prior At-The-Market Program [Member]
Class of Stock [Line Items]
Net proceeds after offering costs and commissions from sale of shares | $													$ 1,700,000	$ 97,000,000.0
Prior At-The-Market Program [Member] | Common stock
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues													92,577	5,871,519
Issuance of common stock, price per share (in dollars per share) | $ / shares											$ 18.23		$ 18.23	$ 16.76
1405 Point
Class of Stock [Line Items]
Noncontrolling interest ownership percentage in properties																79.00%	21.00%
Thames Street Wharf
Class of Stock [Line Items]
Area of retail space | ft²										263,426
Redeemable convertible preferred stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)											9,980,000		9,980,000	2,930,000
Preferred stock, shares issued (in shares)										2,530,000	6,843,418		6,843,418	2,530,000
Preferred stock, shares outstanding (in shares)											6,843,418		6,843,418	2,530,000
Preferred Stock, Convertible, Conversion Price, Maximum | $ / shares													$ 2.97796
Dividend rate										6.75%			6.75%	6.75%
Preferred stock, redemption price (in dollars per share) | $ / shares											$ 25.00		$ 25.00
Preferred stock, par or stated value (in dollars per share) | $ / shares										$ 0.01
Liquidation preference (in dollars per share) | $ / shares										$ 25.00
Proceeds from issuance of preferred stock and preference stock | $										$ 61,300,000
Redeemable convertible preferred stock | Over-Allotment Option
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)										330,000
Redeemable convertible preferred stock | At The Market Program [Member]
Class of Stock [Line Items]
Maximum aggregate offering price of shares to be sold (up to) | $							$ 300,000,000.0
Dividend rate							6.75%
Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)					3,600,000					2,530,000
Dividend rate					6.75%					6.75%
Series A Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)											6,800,000		6,800,000	2,500,000
Preferred stock, shares outstanding (in shares)											6,800,000		6,800,000	2,500,000
Dividends declared (in dollars per share) | $ / shares													$ 1.687500	$ 0.970315
Dividends, Preferred Stock, Stock | $													$ 7,300,000	$ 2,500,000
Series A Cumulative Redeemable Preferred Stock | Subsequent Event
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $			$ 2,900,000
Dividends declared (in dollars per share) | $ / shares		$ 0.421875
Series A Cumulative Redeemable Preferred Stock | The Amendments, At-the-Market Continuous Equity Program [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues													713,418
Net proceeds after offering costs and commissions from sale of shares | $													$ 16,100,000
Sale of stock, weighted average price per share | $ / shares													$ 22.88
Series A Cumulative Redeemable Preferred Stock | Public Stock Offering [Member]
Class of Stock [Line Items]
Net proceeds after offering costs and commissions from sale of shares | $					$ 86,100,000
Number of shares issued in public offering					3,600,000
Issuance of common stock, price per share (in dollars per share) | $ / shares					$ 24.75
Common Class A | Common stock
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues						756,697
Common Class A | Edison Apartments | Operating Partnership
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues				633,734
Noncontrolling interests in Operating Partnership
Class of Stock [Line Items]
Liquidation preference | $											$ 171,100,000		$ 171,100,000
Noncontrolling interests in Operating Partnership | Operating Partnership
Class of Stock [Line Items]
Nonredeemable noncontrolling interest | $											$ 500,000		$ 500,000
Consolidated Entities Under Development Or Construction | Operating Partnership
Class of Stock [Line Items]
Nonredeemable noncontrolling interest | $														$ 4,500,000