Consolidated Statement of Partners' Capital - USD ($) $ in Thousands		Total	Retail Opportunity Investments Partnership L.P.	Retail Opportunity Investments Partnership L.P. Officer	Retail Opportunity Investments Partnership L.P. Limited Partner’s Capital		Retail Opportunity Investments Partnership L.P. Limited Partner’s Capital Officer	Retail Opportunity Investments Partnership L.P. ROIC Capital		Retail Opportunity Investments Partnership L.P. ROIC Capital Officer	[2]	Retail Opportunity Investments Partnership L.P. Accumulated other comprehensive (loss) income
Total (in shares)					11,668,061	[1]		109,301,762	[2]
Balance (in shares) at Dec. 31, 2016					11,668,061	[1]		109,301,762	[2]
Balance at Dec. 31, 2016			$ 1,315,565		$ 127,324	[1]		$ 1,191,970	[2]			$ (3,729)
OP Units issued under the Equity Incentive Plan (in shares)	[2]							353,261
OP Units issued under the Equity Incentive Plan		$ 44	44					$ 44	[2]
OP Units withheld for employee taxes (in shares)	[2]							(74,331)
OP Units withheld for employee taxes		(1,571)	(1,571)					$ (1,571)	[2]
Cancellation of OP Units (in shares)	[2]							(1,999)
Stock based compensation expense		6,190	6,190					$ 6,190	[2]
Issuance of OP Units in connection with acquisition (in shares)	[1]				2,573,927
Issuance of OP Units in connection with acquisition			49,599		$ 49,599	[1]
Equity Redemption of OP Units (in shares)					(2,555,933)	[1]		2,555,933	[2]
Equity Redemption of OP Units					$ 50,155	[1]		$ (50,155)	[2]
Cash redemption of OP Units (in shares)	[1]				(7,064)
Cash redemption of OP Units		(150)	(150)		$ (150)	[1]
Adjustment to non-controlling interests ownership in Operating Partnership					3,574	[1]		$ (3,574)	[2]
Issuance of OP Units in connection with common stock offering (in shares)	[2]							212,825
Issuance of OP Units in connection with common stock offering		4,481	4,481					$ 4,481	[2]
Registration expenditures		(1,045)	(1,045)					(1,045)	[2]
Cash distributions			(91,510)	$ (235)	(8,729)	[1]		(82,781)	[2]	$ (235)
Net income		42,688	42,688		$ 4,211	[1]		$ 38,477	[2]
Other comprehensive income (loss)		5,585	5,585									5,585
Total (in shares)					11,678,991	[1]		112,347,451	[2]
Balance (in shares) at Dec. 31, 2017					11,678,991	[1]		112,347,451	[2]
Balance at Dec. 31, 2017			1,329,641		$ 125,674	[1]		$ 1,202,111	[2]			1,856
Total (in shares)					11,678,991	[1]		112,347,451	[2]
OP Units issued under the Equity Incentive Plan (in shares)	[2]							397,861
OP Units issued under the Equity Incentive Plan		269	269					$ 269	[2]
OP Units withheld for employee taxes (in shares)	[2]							(70,168)
OP Units withheld for employee taxes		(1,400)	(1,400)					$ (1,400)	[2]
Cancellation of OP Units (in shares)	[2]							(8,997)
Stock based compensation expense		7,392	7,392					$ 7,392	[2]
Cash redemption of OP Units (in shares)	[1]				(201,950)
Cash redemption of OP Units		(3,713)	(3,713)		$ (3,713)	[1]
Adjustment to non-controlling interests ownership in Operating Partnership					2,904	[1]		$ (2,904)	[2]
Issuance of OP Units in connection with common stock offering (in shares)	[2]							1,326,690
Issuance of OP Units in connection with common stock offering		25,703	25,703					$ 25,703	[2]
Registration expenditures		(570)	(570)					(570)	[2]
Cash distributions			(97,473)	(267)	(9,056)	[1]		(88,417)	[2]	(267)
Net income		47,141	47,141		$ 4,405	[1]		$ 42,736	[2]
Other comprehensive income (loss)		1,705	1,705									1,705
Total (in shares)					11,477,041	[1]		113,992,837	[2]
Balance (in shares) at Dec. 31, 2018					11,477,041	[1]		113,992,837	[2]
Balance at Dec. 31, 2018			1,308,428		$ 120,214	[1]		$ 1,184,653	[2]			3,561
Total (in shares)					11,477,041	[1]		113,992,837	[2]
OP Units issued under the Equity Incentive Plan (in shares)	[2]							631,022
OP Units issued under the Equity Incentive Plan		1,942	1,942					$ 1,942	[2]
OP Units withheld for employee taxes (in shares)	[2]							(125,072)
OP Units withheld for employee taxes		(1,986)	(1,986)					$ (1,986)	[2]
Cancellation of OP Units (in shares)	[2]							(6,997)
Stock based compensation expense		$ 8,567	8,567		$ 1,215	[1]		$ 7,352	[2]
Equity Redemption of OP Units (in shares)		143,190			(143,190)	[1]		143,190	[2]
Equity Redemption of OP Units					$ 2,632	[1]		$ (2,632)	[2]
Cash redemption of OP Units (in shares)		(282,761)			(282,761)	[1]
Cash redemption of OP Units		$ (5,043)	(5,043)		$ (5,043)	[1]
Adjustment to non-controlling interests ownership in Operating Partnership					2,983	[1]		$ (2,983)	[2]
Issuance of OP Units in connection with common stock offering (in shares)	[2]							1,861,036
Issuance of OP Units in connection with common stock offering		34,162	34,162					$ 34,162	[2]
Registration expenditures		(732)	(732)					(732)	[2]
Cash distributions			(99,470)	$ (30)	(8,921)	[1]	$ (175)	(90,549)	[2]	$ 145
Net income		53,683	53,683		$ 4,839	[1]		$ 48,844	[2]
Other comprehensive income (loss)		$ (7,693)	(7,693)									(7,693)
Total (in shares)		127,547,106			11,051,090	[1]		116,496,016	[2]
Balance (in shares) at Dec. 31, 2019		127,547,106			11,051,090	[1]		116,496,016	[2]
Balance at Dec. 31, 2019			$ 1,291,828		$ 112,480	[1]		$ 1,183,480	[2]			$ (4,132)
Total (in shares)		127,547,106			11,051,090	[1]		116,496,016	[2]

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

[2] Consists of general and limited partnership interests held by ROIC.