Capital of the Operating Partnership (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Jun. 30, 2023	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Limited Partners' Capital Account [Line Items]
Partnership units (in shares)		134,891,471		134,891,471
Common stock, shares outstanding (in shares)		128,648,870		128,648,870			126,904,085
Notices of redemptions received (in shares)				1,194,516
Equity Redemption of OP Units (in shares)				1,194,516
ROIC
Limited Partners' Capital Account [Line Items]
ROIC ownership percentage in ROIP LP				95.30%
Common Stock
Limited Partners' Capital Account [Line Items]
Common stock, shares outstanding (in shares)		128,648,870	126,003,795	128,648,870	127,454,354	127,457,854	126,904,085	126,001,795	125,024,887	124,538,811
Equity Redemption of OP Units (in shares)		1,194,516	1,010,000	1,194,516
OP Units
Limited Partners' Capital Account [Line Items]
Non-controlling interest redemption value		$ 98.3		$ 98.3
Redemption value (usd per share)		$ 15.74		$ 15.74
Limited Partner’s Capital | Retail Opportunity Investments Partnership L.P.
Limited Partners' Capital Account [Line Items]
Partnership units (in shares)	[1]	6,242,601	7,437,117	6,242,601	7,437,117	7,437,117	7,437,117	7,437,117	8,447,117	8,447,117
Equity Redemption of OP Units (in shares)	[1]	(1,194,516)	(1,010,000)

[1] Consists of limited partnership interests held by third parties.