Consolidated Statement of Partners' Capital - USD ($) $ in Thousands		Total	Common Stock	Non- controlling interests	Additional paid-in capital	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 income (loss)
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
Increase (Decrease) in Partners' Capital [Roll Forward]
OP units issued under the Equity Incentive Plan (in shares)			445,022									445,022	[2]
OP Units issued under the Equity Incentive Plan		$ 0			$ 0	0						$ 0	[2]
OP Units withheld for employee taxes (in shares)			(125,072)									(125,072)	[2]
OP Units withheld for employee taxes		(1,986)			(1,986)	(1,986)						$ (1,986)	[2]
Cancellation of OP Units (in shares)			(999)									(999)	[2]
Stock based compensation expense		1,651			1,651	1,651						$ 1,651	[2]
Cash redemption of OP Units (in units)	[1]							(70,000)
Cash redemption for non-controlling interests		(1,246)		$ (1,246)		(1,246)		$ (1,246)	[1]
Adjustment to non-controlling interests ownership in Operating Partnership				(56)	56			(56)	[1]			56	[2]
Registration expenditures		(47)			(47)	(47)						(47)	[2]
Cash distributions						(24,766)	$ 142	(2,247)	[1]			(22,519)	[2]	$ 142
Net income attributable to Retail Opportunity Investments Partnership, LP						14,583		$ 1,333	[1]			$ 13,250	[2]
Other comprehensive gain (loss)		(2,810)				(2,810)										(2,810)
Balance (in shares) at Mar. 31, 2019								11,407,041	[1]			114,311,788	[2]
Balance at Mar. 31, 2019						1,293,949		$ 117,998	[1]			$ 1,175,200	[2]			751
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
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income attributable to Retail Opportunity Investments Partnership, LP		22,929				22,929
Balance (in shares) at Jun. 30, 2019								11,407,041	[1]			114,307,789	[2]
Balance at Jun. 30, 2019						1,274,594		$ 116,233	[1]			$ 1,162,688	[2]			(4,327)
Balance (in shares) at Mar. 31, 2019								11,407,041	[1]			114,311,788	[2]
Balance at Mar. 31, 2019						1,293,949		$ 117,998	[1]			$ 1,175,200	[2]			751
Increase (Decrease) in Partners' Capital [Roll Forward]
Cancellation of OP Units (in shares)			(3,999)									(3,999)	[2]
Stock based compensation expense		2,239		387	1,852	2,239		387				$ 1,852	[2]
Adjustment to non-controlling interests ownership in Operating Partnership				(592)	592			(592)	[1]			592	[2]
Registration expenditures		(33)			(33)	(33)						(33)	[2]
Cash distributions						(24,764)	(65)	(2,247)	[1]	$ (74)		(22,517)	[2]	9
Net income attributable to Retail Opportunity Investments Partnership, LP		8,346				8,346		$ 761	[1]			$ 7,585	[2]
Other comprehensive gain (loss)		(5,078)				(5,078)										(5,078)
Balance (in shares) at Jun. 30, 2019								11,407,041	[1]			114,307,789	[2]
Balance at Jun. 30, 2019						1,274,594		$ 116,233	[1]			$ 1,162,688	[2]			(4,327)
Balance (in shares) at Dec. 31, 2019								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)
Increase (Decrease) in Partners' Capital [Roll Forward]
OP units issued under the Equity Incentive Plan (in shares)			428,170									428,170	[2]
OP Units issued under the Equity Incentive Plan		0			0	0						$ 0	[2]
OP Units withheld for employee taxes (in shares)			(128,614)									(128,614)	[2]
OP Units withheld for employee taxes		(2,272)			(2,272)	(2,272)						$ (2,272)	[2]
Cancellation of OP Units (in shares)			(1,000)									(1,000)	[2]
Stock based compensation expense		1,856		220	1,636	1,856		$ 220	[1]			$ 1,636	[2]
Cash redemption of OP Units (in units)	[1]							(116,657)
Cash redemption for non-controlling interests		(1,999)		(1,999)		(1,999)		$ (1,999)	[1]
Adjustment to non-controlling interests ownership in Operating Partnership				(652)	652			(652)	[1]			$ 652	[2]
Repurchase of OP units (in shares)			(673,868)									(673,868)	[2]
Repurchase of OP Units		(8,846)			(8,846)							$ (8,846)	[2]
Registration expenditures		(90)			(90)	(90)						(90)	[2]
Cash distributions						(25,460)	$ (89)	(2,187)	[1]	$ (33)	[1]	(23,273)	[2]	$ (56)
Net income attributable to Retail Opportunity Investments Partnership, LP						13,136		$ 1,134	[1]			$ 12,002	[2]
Other comprehensive gain (loss)		$ (8,717)				(8,717)										(8,717)
Balance (in shares) at Mar. 31, 2020								10,934,433	[1]			116,120,704	[2]
Balance at Mar. 31, 2020						1,259,347		$ 108,963	[1]			$ 1,163,233	[2]			(12,849)
Balance (in shares) at Dec. 31, 2019								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)
Increase (Decrease) in Partners' Capital [Roll Forward]
Equity Redemption of OP Units, Shares		1,521,833	1,521,833
Redemption of OP Units		$ 15,211				15,211
Repurchase of OP units (in shares)		(673,868)
Repurchase of OP Units		$ (8,800)
Net income attributable to Retail Opportunity Investments Partnership, LP		$ 18,172				18,172
Balance (in shares) at Jun. 30, 2020		127,052,638						9,412,600	[1]			117,640,038	[2]
Balance at Jun. 30, 2020						1,266,821		$ 95,292	[1]			$ 1,184,114	[2]			(12,585)
Balance (in shares) at Mar. 31, 2020								10,934,433	[1]			116,120,704	[2]
Balance at Mar. 31, 2020						1,259,347		$ 108,963	[1]			$ 1,163,233	[2]			(12,849)
Increase (Decrease) in Partners' Capital [Roll Forward]
Cancellation of OP Units (in shares)			(2,499)									(2,499)	[2]
Stock based compensation expense		$ 2,168		87	2,081	2,168		$ 87	[1]			$ 2,081	[2]
Equity Redemption of OP Units, Shares			1,521,833					1,521,833				1,521,833
Redemption of OP Units				(15,211)	15,211			$ (15,211)				$ 15,211
Adjustment to non-controlling interests ownership in Operating Partnership				1,064	(1,064)			1,064	[1]			(1,064)	[2]
Registration expenditures		6			$ 6	6						6	[2]
Net income attributable to Retail Opportunity Investments Partnership, LP		5,036				5,036		$ 389	[1]			$ 4,647	[2]
Other comprehensive gain (loss)		$ 264		$ (937)		264										264
Balance (in shares) at Jun. 30, 2020		127,052,638						9,412,600	[1]			117,640,038	[2]
Balance at Jun. 30, 2020						$ 1,266,821		$ 95,292	[1]			$ 1,184,114	[2]			$ (12,585)

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

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