Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 11,824	$ 11,251
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	25,217	23,058
Amortization of deferred financing costs and mortgage premiums, net	449	532
Straight-line rent adjustment	(1,471)	(1,066)
Amortization of above and below market rent	(4,075)	(6,049)
Amortization relating to stock based compensation	1,428	1,217
Provisions for tenant credit losses	323	636
Other noncash interest expense	535	535
Change in operating assets and liabilities:
Tenant and other receivables	845	304
Prepaid expenses	(89)	837
Accounts payable and accrued expenses	9,701	7,416
Other assets and liabilities, net	(264)	980
Net cash provided by operating activities	44,423	39,651
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in real estate	(19,337)	(88,187)
Improvements to properties	(8,441)	(7,337)
Deposits on real estate acquisitions, net	0	(2,000)
Net cash used in investing activities	(27,778)	(97,524)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal repayments on mortgages	(10,317)	(189)
Proceeds from draws on credit facility	45,000	99,000
Payments on credit facility	(29,000)	(10,000)
Distributions to OP Unitholders	(2,277)	(2,099)
Deferred financing and other costs	0	(3)
Proceeds from the sale of common stock	1,508	0
Registration expenditures	(48)	(256)
Dividends paid to common shareholders	(22,066)	(20,709)
Common shares/OP Units issued under the 2009 Plan	0	43
Shares withheld for employee taxes	(1,400)	(1,571)
Net cash (used in) provided by financing activities	(18,600)	64,216
Net (decrease) increase in cash, cash equivalents and restricted cash	(1,955)	6,343
Cash, cash equivalents and restricted cash at beginning of period	16,965	13,250
Cash, cash equivalents and restricted cash at end of period	15,010	19,593
Other non-cash investing and financing activities:
Issuance of OP Units in connection with acquisitions	0	3,559
Intangible lease liabilities	0	1,118
Interest rate swap asset	3,273	181
Accrued real estate improvement costs	2,196	1,531
Reconciliation of cash, cash equivalents and restricted cash [Abstract]
Cash and cash equivalents	13,012	19,430
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	11,824	11,251
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	25,217	23,058
Amortization of deferred financing costs and mortgage premiums, net	449	532
Straight-line rent adjustment	(1,471)	(1,066)
Amortization of above and below market rent	(4,075)	(6,049)
Amortization relating to stock based compensation	1,428	1,217
Provisions for tenant credit losses	323	636
Other noncash interest expense	535	535
Change in operating assets and liabilities:
Tenant and other receivables	845	304
Prepaid expenses	(89)	837
Accounts payable and accrued expenses	9,701	7,416
Other assets and liabilities, net	(264)	980
Net cash provided by operating activities	44,423	39,651
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in real estate	(19,337)	(88,187)
Improvements to properties	(8,441)	(7,337)
Deposits on real estate acquisitions, net	0	(2,000)
Net cash used in investing activities	(27,778)	(97,524)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal repayments on mortgages	(10,317)	(189)
Proceeds from draws on credit facility	45,000	99,000
Payments on credit facility	(29,000)	(10,000)
Distributions to OP Unitholders	(24,343)	(22,808)
Deferred financing and other costs	0	(3)
Proceeds from the sale of common stock	1,508	0
Registration expenditures	(48)	(256)
Common shares/OP Units issued under the 2009 Plan	0	43
Shares withheld for employee taxes	(1,400)	(1,571)
Net cash (used in) provided by financing activities	(18,600)	64,216
Net (decrease) increase in cash, cash equivalents and restricted cash	(1,955)	6,343
Cash, cash equivalents and restricted cash at beginning of period	16,965	13,250
Cash, cash equivalents and restricted cash at end of period	15,010	19,593
Other non-cash investing and financing activities:
Issuance of OP Units in connection with acquisitions	0	3,559
Intangible lease liabilities	0	1,118
Interest rate swap asset	3,273	181
Accrued real estate improvement costs	2,196	1,531
Reconciliation of cash, cash equivalents and restricted cash [Abstract]
Cash and cash equivalents	13,012	19,430
Total cash, cash equivalents and restricted cash shown in Statements of Cash Flow	$ 16,965	$ 13,250