Equity - Additional Information (Details) - USD ($)							3 Months Ended		12 Months Ended
	Feb. 20, 2020	Jan. 15, 2020	Jan. 02, 2020	Aug. 06, 2019	Jun. 18, 2019	May 04, 2016	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Mar. 06, 2020
Class of Stock
Preferred stock, shares authorized (in shares)							100,000,000		100,000,000
Net proceeds from issuance of common and preferred stock							$ 1,349,000	$ 30,206,000
Preferred stock, par value (in dollars per share)							$ 0.01		$ 0.01
Percentage of operating partnership held							72.60%		72.60%
Aggregate cash dividends and distributions, paid							$ 17,373,000	$ 13,447,000
Dividends and distributions declared per common share and unit (in dollars per share)							$ 0.22	$ 0.21
Class A units
Class of Stock
Class A Units not held by Company (in shares)							21,272,962
Class A units | Operating Partnership
Class of Stock
Aggregate cash dividends and distributions, paid			$ 4,500,000
Common stock
Class of Stock
Net proceeds from issuance of common and preferred stock							$ 1,000	$ 21,000
Aggregate cash dividends and distributions, paid			$ 11,800,000
New ATM Program | Common stock
Class of Stock
Maximum aggregate offering price of shares to be sold (up to)				$ 180,700,000
The Amendments
Class of Stock
Consideration received on transaction							$ 1,700,000
The Amendments | Common stock
Class of Stock
Shares issued (in shares)							92,577
Weighted average price (in dollars per share)							$ 18.23
At The Market Program
Class of Stock
Preferred stock, shares authorized (in shares)										400,000
Noncontrolling interests in investment entities
Class of Stock
Liquidation preference							$ 63,300,000
Noncontrolling interests in investment entities | Operating Partnership
Class of Stock
Ownership interest percentage in properties							$ 4,400,000
Consolidated Entities Under Development Or Construction | Operating Partnership
Class of Stock
Ownership interest percentage in properties									$ 4,500,000
Common stock
Class of Stock
Dividends and distributions declared per common share and unit (in dollars per share)	$ 0.22
Redeemable convertible preferred stock
Class of Stock
Preferred stock, shares authorized (in shares)							2,930,000		2,930,000
Preferred Stock dividend rate percentage					6.75%		6.75%		6.75%
Aggregate cash dividends and distributions, paid		$ 1,100,000
Redeemable convertible preferred stock | Preferred stock
Class of Stock
Preferred stock, dividends declared (in dollars per share)	$ 0.421875
Redeemable convertible preferred stock | At The Market Program
Class of Stock
Maximum aggregate offering price of shares to be sold (up to)						$ 300,000,000.0
Preferred Stock dividend rate percentage					6.75%
Construction loans
Class of Stock
Borrowings under construction loans							$ 18,900,000