Consolidated Statement of Partners' Capital - USD ($) $ in Thousands	Total	Officer [Member]	Retail Opportunity Investments Partnership L.P.	Retail Opportunity Investments Partnership L.P. Officer [Member]	Retail Opportunity Investments Partnership L.P. Limited Partner’s Capital	Retail Opportunity Investments Partnership L.P. ROIC Capital	Retail Opportunity Investments Partnership L.P. ROIC Capital Officer [Member]	Retail Opportunity Investments Partnership L.P. Accumulated other comprehensive loss	Two Thousand and Nine Stock Plan [Member] Retail Opportunity Investments Partnership L.P. ROIC Capital	Common Stock Retail Opportunity Investments Partnership L.P.	Common Stock Retail Opportunity Investments Partnership L.P. ROIC Capital
Increase (Decrease) in Partners' Capital [Roll Forward]
Total (in shares)					12,195,603	99,531,034
Balance (in shares) at Dec. 31, 2015					12,195,603	99,531,034
Balance at Dec. 31, 2015			$ 1,131,342		$ 94,671	$ 1,043,414		$ (6,743)
Increase (Decrease) in Partners' Capital [Roll Forward]
OP units issued under the 2009 Plan (in shares)									337,556
Repurchase of OP Units (in shares)						(75,472)
Repurchase of OP Units	$ (1,351)		(1,351)			$ (1,351)
Cancellation of restricted stock (in shares)						(833)
Stock based compensation expense	2,568		2,568			$ 2,568
Issuance of OP Units (in shares)					2,434,833						1,943,059
Issuance of OP Units	$ 48,175		48,175		$ 48,175
Equity redemption of OP Units (in shares)	244,126				(244,126)	244,126
OP Unit redemption	$ 4,730		4,730		$ (4,730)	$ 4,730
Cash redemption of OP Units (in shares)					(2,206,613)
Cash redemption of OP Units	(7,182)		(7,182)		$ (7,182)
Adjustment to non-controlling interests ownership in Operating Partnership					(7,157)	7,157
Issuance of OP Units in connection with sale of common stock	39,964									$ 39,964	$ 39,964
Registration expenditures	(742)		(742)			(742)
Cash distributions ($0.36 per unit)			(40,351)		(4,137)	(36,214)
Dividends payable to officers	(40,351)	$ (89)		$ (89)			$ (89)
Net income attributable to Retail Opportunity Investments Partnership, LP	17,563		17,563		$ 1,832	$ 15,731
Other comprehensive income	415		415					415
Total (in shares)					12,195,603	99,531,034
Proceeds on repayment of promissory note receivable secured by capital	$ 6,710		6,710		$ 6,710
Balance (in shares) at Jun. 30, 2016					12,179,697	101,979,470
Balance at Jun. 30, 2016			1,197,022		$ 128,182	$ 1,075,168		(6,328)
Increase (Decrease) in Partners' Capital [Roll Forward]
Total (in shares)					12,179,697	101,979,470
Total			$ 1,190,312		$ 121,472	$ 1,075,168		$ (6,328)