Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 36,430	$ 25,092	$ 21,050
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	88,359	70,957	58,435
Amortization of deferred financing costs and mortgage premiums, net	2,088	662	(432)
Straight-line rent adjustment	(4,560)	(5,013)	(3,795)
Amortization of above and below market rent	(13,847)	(9,890)	(6,945)
Amortization relating to stock based compensation	4,916	4,684	3,662
Provisions for tenant credit losses	1,805	1,984	2,316
Other noncash interest expense	2,139	2,139	1,848
Gain on sale of real estate	0	0	(4,869)
Settlement of interest rate swap agreements	0	0	(3,230)
Change in operating assets and liabilities:
Restricted cash	66	264	190
Tenant and other receivables	(4,412)	(2,599)	(1,605)
Prepaid expenses	(1,363)	501	(1,106)
Accounts payable and accrued expenses	4,417	512	(1,164)
Other assets and liabilities, net	(1,356)	(2,376)	852
Net cash provided by operating activities	114,682	86,917	65,207
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in real estate	(284,867)	(313,623)	(398,205)
Proceeds from sale of real estate	0	0	27,622
Improvements to properties	(40,758)	(27,515)	(26,142)
Deposits on real estate acquisitions, net	500	4,000	(3,725)
Construction escrows and other	35	23	594
Net cash used in investing activities	(325,090)	(337,115)	(399,856)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal repayments on mortgages	(7,816)	(84,308)	(21,982)
Proceeds from new mortgage loan	0	35,500	0
Proceeds from term loan	0	300,000	0
Payments on term loan	0	0	(200,000)
Proceeds from draws on credit facility	332,500	430,000	549,300
Payments on credit facility	(370,000)	(451,000)	(449,750)
Proceeds from the issuance of OP Units upon exercise of warrants	0	0	70,723
Issuance of promissory note receivable	0	(6,710)	0
Proceeds on repayment of promissory note receivable	6,710	0	0
Redemption of OP Units	(38,820)	0	(3,280)
Distributions to OP Unitholders	(8,363)	(2,764)	(2,009)
Deferred financing and other costs	(266)	(1,849)	(3,188)
Proceeds from the issuance of OP Units in connection with issuance of common stock	184,881	101,293	214,906
Registration expenditures	(7,097)	(4,739)	(9,513)
Dividends paid to common shareholders	(75,672)	(65,837)	(53,574)
Repurchase of common stock	(1,368)	(1,317)	(631)
Net cash provided by financing activities	214,689	248,269	337,502
Net increase (decrease) in cash and cash equivalents	4,281	(1,929)	2,853
Cash and cash equivalents at beginning of period	8,844	10,773	7,920
Cash and cash equivalents at end of period	13,125	8,844	10,773
Supplemental disclosure of cash activities:
Cash paid on gross receipts and income for federal and state purposes	206	241	331
Interest paid	34,275	31,996	26,006
Other non-cash investing and financing activities – increase (decrease):
Issuance of OP Units in connection with acquisitions	46,140	150,315	16,343
Assumed mortgages in connection with acquisitions	17,618	19,024	0
Intangible lease liabilities	32,615	37,480	44,264
Interest rate swap asset	875	0	(1,948)
Interest rate swap liabilities	0	0	(2,529)
Accrued real estate improvement costs	601	590	1,372
Equity redemption of OP Units	15,990	3,184	0
Retail Opportunity Investments Partnership L.P.
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	36,430	25,092	21,050
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	88,359	70,957	58,435
Amortization of deferred financing costs and mortgage premiums, net	2,088	662	(432)
Straight-line rent adjustment	(4,560)	(5,013)	(3,795)
Amortization of above and below market rent	(13,847)	(9,890)	(6,945)
Amortization relating to stock based compensation	4,916	4,684	3,662
Provisions for tenant credit losses	1,805	1,984	2,316
Other noncash interest expense	2,139	2,139	1,848
Gain on sale of real estate	0	0	(4,869)
Settlement of interest rate swap agreements	0	0	(3,230)
Change in operating assets and liabilities:
Restricted cash	66	264	190
Tenant and other receivables	(4,412)	(2,599)	(1,605)
Prepaid expenses	(1,363)	501	(1,106)
Accounts payable and accrued expenses	4,417	512	(1,164)
Other assets and liabilities, net	(1,356)	(2,376)	852
Net cash provided by operating activities	114,682	86,917	65,207
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in real estate	(284,867)	(313,623)	(398,205)
Proceeds from sale of real estate	0	0	27,622
Improvements to properties	(40,758)	(27,515)	(26,142)
Deposits on real estate acquisitions, net	500	4,000	(3,725)
Construction escrows and other	35	23	594
Net cash used in investing activities	(325,090)	(337,115)	(399,856)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal repayments on mortgages	(7,816)	(84,308)	(21,982)
Proceeds from new mortgage loan	0	35,500	0
Proceeds from term loan	0	300,000	0
Payments on term loan	0	0	(200,000)
Proceeds from draws on credit facility	332,500	430,000	549,300
Payments on credit facility	(370,000)	(451,000)	(449,750)
Proceeds from the issuance of OP Units upon exercise of warrants	0	0	70,723
Issuance of promissory note receivable	0	(6,710)	0
Proceeds on repayment of promissory note receivable	6,710	0	0
Redemption of OP Units	(38,820)	0	(3,280)
Distributions to OP Unitholders	(84,035)	(68,601)	(55,583)
Deferred financing and other costs	(266)	(1,849)	(3,188)
Proceeds from the issuance of OP Units in connection with issuance of common stock	184,881	101,293	214,906
Registration expenditures	(7,097)	(4,739)	(9,513)
Repurchase of common stock	(1,368)	(1,317)	(631)
Net cash provided by financing activities	214,689	248,269	337,502
Net increase (decrease) in cash and cash equivalents	4,281	(1,929)	2,853
Cash and cash equivalents at beginning of period	8,844	10,773	7,920
Cash and cash equivalents at end of period	13,125	8,844	10,773
Supplemental disclosure of cash activities:
Cash paid on gross receipts and income for federal and state purposes	206	241	331
Interest paid	34,275	31,996	26,006
Other non-cash investing and financing activities – increase (decrease):
Issuance of OP Units in connection with acquisitions	46,140	150,315	16,343
Assumed mortgages in connection with acquisitions	17,618	19,024	0
Intangible lease liabilities	32,615	37,480	44,264
Interest rate swap asset	875	0	(1,948)
Interest rate swap liabilities	0	0	(2,529)
Accrued real estate improvement costs	601	590	1,372
Equity redemption of OP Units	15,990	3,184	0
Senior Notes Due 2026
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of senior notes	200,000	0	0
Senior Notes Due 2024
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of senior notes	0	0	246,500
Senior Notes | Senior Notes Due 2026 | Retail Opportunity Investments Partnership L.P.
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of senior notes	200,000	0	0
Senior Notes | Senior Notes Due 2024 | Retail Opportunity Investments Partnership L.P.
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of senior notes	$ 0	$ 0	$ 246,500