Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 19,926	$ 20,448
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	50,548	46,703
Amortization of deferred financing costs and mortgage premiums, net	926	1,067
Straight-line rent adjustment	(2,881)	(2,340)
Amortization of above and below market rent	(7,218)	(9,319)
Amortization relating to stock based compensation	3,419	2,873
Provisions for tenant credit losses	789	979
Other noncash interest expense	1,070	1,070
Change in operating assets and liabilities:
Tenant and other receivables	3,254	535
Prepaid expenses	1,252	2,150
Accounts payable and accrued expenses	(2,925)	(1,393)
Other assets and liabilities, net	(1,248)	977
Net cash provided by operating activities	66,912	63,750
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in real estate	(39,176)	(168,672)
Improvements to properties	(21,662)	(18,760)
Deposits on real estate acquisitions, net	500	(5,000)
Net cash used in investing activities	(60,338)	(192,432)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal repayments on mortgages	(10,493)	(8,498)
Proceeds from draws on credit facility	110,000	193,000
Payments on credit facility	(61,500)	(10,000)
Redemption of OP Units	(560)	(150)
Deferred financing and other costs	0	(3)
Proceeds from the sale of common stock	1,508	0
Registration expenditures	(118)	(348)
Distributions to OP Unitholders	(4,553)	(4,349)
Dividends paid to common shareholders	(44,045)	(41,284)
Common shares/OP Units issued under the Equity Incentive Plan	0	43
Shares withheld for employee taxes	(1,400)	(1,571)
Net cash (used in) provided by financing activities	(11,161)	126,840
Net decrease in cash, cash equivalents and restricted cash	(4,587)	(1,842)
Cash, cash equivalents and restricted cash at beginning of period	16,965	13,250
Cash, cash equivalents and restricted cash at end of period	12,378	11,408
Other non-cash investing and financing activities:
Issuance of OP Units in connection with acquisitions	0	3,559
Intangible lease liabilities	925	14,355
Interest rate swap asset	4,309	80
Accrued real estate improvement costs	(1,074)	2,822
Redemption / Exchange of OP Units	0	3,202
Reconciliation of cash, cash equivalents and restricted cash [Abstract]
Cash and cash equivalents	10,958	11,408
Total cash, cash equivalents and restricted cash shown in Statements of Cash Flow	16,965	13,250
Retail Opportunity Investments Partnership L.P.
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	19,926	20,448
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	50,548	46,703
Amortization of deferred financing costs and mortgage premiums, net	926	1,067
Straight-line rent adjustment	(2,881)	(2,340)
Amortization of above and below market rent	(7,218)	(9,319)
Amortization relating to stock based compensation	3,419	2,873
Provisions for tenant credit losses	789	979
Other noncash interest expense	1,070	1,070
Change in operating assets and liabilities:
Tenant and other receivables	3,254	535
Prepaid expenses	1,252	2,150
Accounts payable and accrued expenses	(2,925)	(1,393)
Other assets and liabilities, net	(1,248)	977
Net cash provided by operating activities	66,912	63,750
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in real estate	(39,176)	(168,672)
Improvements to properties	(21,662)	(18,760)
Deposits on real estate acquisitions, net	500	(5,000)
Net cash used in investing activities	(60,338)	(192,432)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal repayments on mortgages	(10,493)	(8,498)
Proceeds from draws on credit facility	110,000	193,000
Payments on credit facility	(61,500)	(10,000)
Redemption of OP Units	(560)	(150)
Deferred financing and other costs	0	(3)
Proceeds from the sale of common stock	1,508	0
Registration expenditures	(118)	(348)
Distributions to OP Unitholders	(48,598)	(45,633)
Common shares/OP Units issued under the Equity Incentive Plan	0	43
Shares withheld for employee taxes	(1,400)	(1,571)
Net cash (used in) provided by financing activities	(11,161)	126,840
Net decrease in cash, cash equivalents and restricted cash	(4,587)	(1,842)
Cash, cash equivalents and restricted cash at beginning of period	16,965	13,250
Cash, cash equivalents and restricted cash at end of period	12,378	11,408
Other non-cash investing and financing activities:
Issuance of OP Units in connection with acquisitions	0	3,559
Intangible lease liabilities	925	14,355
Interest rate swap asset	4,309	80
Accrued real estate improvement costs	(1,074)	2,822
Redemption / Exchange of OP Units	0	3,202
Reconciliation of cash, cash equivalents and restricted cash [Abstract]
Cash and cash equivalents	10,958	11,408
Total cash, cash equivalents and restricted cash shown in Statements of Cash Flow	$ 16,965	$ 13,250