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	[1]	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)	[2]								445,022
OP Units issued under the Equity Incentive Plan		$ 0	0						$ 0	[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]								(999)
Stock based compensation expense		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]
Adjustment to non-controlling interests ownership in Operating Partnership					(56)	[1]			56	[2]
Registration expenditures		(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	14,583		$ 1,333	[1]			$ 13,250	[2]
Other comprehensive 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, 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)	[2]								428,170
OP Units issued under the Equity Incentive Plan		0	0						$ 0	[2]
OP Units withheld for employee taxes (in shares)	[2]								(128,614)
OP Units withheld for employee taxes		(2,272)	(2,272)						$ (2,272)	[2]
Cancellation of OP Units (in shares)	[2]								(1,000)
Stock based compensation expense		1,856	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]
Adjustment to non-controlling interests ownership in Operating Partnership					(652)	[1]			$ 652	[2]
Repurchase of OP units (in shares)		(673,868)							(673,868)	[2]
Repurchase of OP Units		$ (8,846)							$ (8,846)	[2]
Registration expenditures		(90)	(90)						(90)	[2]
Cash distributions			(25,460)	$ (89)	(2,187)	[1]	$ (33)		(23,273)	[2]	$ (56)
Net income attributable to Retail Opportunity Investments Partnership, LP		13,136	13,136		$ 1,134	[1]			$ 12,002	[2]
Other comprehensive loss		$ (8,717)	(8,717)										(8,717)
Balance (in shares) at Mar. 31, 2020		127,055,137			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)

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

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