Common Stock of ROIC (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Feb. 20, 2020	Jul. 31, 2013
Class of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
Proceeds from the sale of common stock	$ 14,211,000	$ 0
Stock issuance costs	$ 351,000	$ 15,000
Stock repurchase program, authorized amount					$ 50,000,000
Repurchase of common stock (in shares)	0
Sales Agreement
Class of Stock [Line Items]
Common stock, par value (in dollars per share)				$ 0.0001
Common shares that may be sold under a sales agreement, aggregate offering price, maximum				$ 500,000,000
Common stock issued, in shares	724,279
Proceeds from the sale of common stock	$ 14,200,000
Stock issuance costs	$ 142,000