Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Officer	Common Stock	Additional paid-in capital	Accumulated dividends in excess of earnings	Accumulated dividends in excess of earnings Officer	Accumulated other comprehensive (loss) income	Non- controlling interests	Non- controlling interests Officer
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total (in shares)			109,301,762
Balance at Dec. 31, 2016	$ 1,315,565		$ 11	$ 1,357,910	$ (165,951)		$ (3,729)	$ 127,324
Balance (in shares) at Dec. 31, 2016			109,301,762
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued under the Equity Incentive Plan (in shares)			353,261
Shares issued under the Equity Incentive Plan	44			44
Shares withheld for employee taxes (in shares)			(74,331)
Shares withheld for employee taxes	(1,571)			(1,571)
Cancellation of restricted stock (in shares)			(1,999)
Stock based compensation expense	6,190			6,190
Issuance of OP Units to non-controlling interests	49,599							49,599
Equity Redemption of OP Units (in shares)			2,555,933
Equity redemption of OP Units	50,155			50,155				(50,155)
Cash redemption for non-controlling interests	(150)							(150)
Adjustment to non-controlling interests ownership in Operating Partnership				(3,574)				3,574
Proceeds from the issuance of common stock (in shares)			212,825
Proceeds from the issuance of common stock	4,481		$ 0	4,481
Registration expenditures	(1,045)			(1,045)
Cash dividends	(91,510)	$ (235)			(82,781)	$ (235)		(8,729)
Net income attributable to Retail Opportunity Investments Corp.	38,477				38,477
Net income attributable to non-controlling interests	4,211							4,211
Other comprehensive income (loss)	5,585						5,585
Total (in shares)			112,347,451
Balance (in shares) at Dec. 31, 2017			112,347,451
Balance at Dec. 31, 2017	1,329,641		$ 11	1,412,590	(210,490)		1,856	125,674
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total (in shares)			112,347,451
Shares issued under the Equity Incentive Plan (in shares)			397,861
Shares issued under the Equity Incentive Plan	269			269
Shares withheld for employee taxes (in shares)			(70,168)
Shares withheld for employee taxes	(1,400)			(1,400)
Cancellation of restricted stock (in shares)			(8,997)
Stock based compensation expense	7,392			7,392
Equity redemption of OP Units	0
Cash redemption for non-controlling interests	(3,713)							(3,713)
Adjustment to non-controlling interests ownership in Operating Partnership				(2,904)				2,904
Proceeds from the issuance of common stock (in shares)			1,326,690
Proceeds from the issuance of common stock	25,703		$ 0	25,703
Registration expenditures	(570)			(570)
Cash dividends	(97,473)	(267)			(88,417)	(267)		(9,056)
Net income attributable to Retail Opportunity Investments Corp.	42,736				42,736
Net income attributable to non-controlling interests	4,405							4,405
Other comprehensive income (loss)	$ 1,705						1,705
Total (in shares)	113,992,837		113,992,837
Balance (in shares) at Dec. 31, 2018	113,992,837		113,992,837
Balance at Dec. 31, 2018	$ 1,308,428		$ 11	1,441,080	(256,438)		3,561	120,214
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total (in shares)	113,992,837		113,992,837
Shares issued under the Equity Incentive Plan (in shares)			631,022
Shares issued under the Equity Incentive Plan	$ 1,942			1,942
Shares withheld for employee taxes (in shares)			(125,072)
Shares withheld for employee taxes	(1,986)			(1,986)
Cancellation of restricted stock (in shares)			(6,997)
Stock based compensation expense	$ 8,567			7,352				1,215
Equity Redemption of OP Units (in shares)	143,190		143,190
Equity redemption of OP Units	$ 2,632			2,632				(2,632)
Cash redemption for non-controlling interests	(5,043)							(5,043)
Adjustment to non-controlling interests ownership in Operating Partnership				(2,983)				2,983
Proceeds from the issuance of common stock (in shares)			1,861,036
Proceeds from the issuance of common stock	34,162		$ 1	34,161
Registration expenditures	(732)			(732)
Cash dividends	(99,470)	$ (30)			(90,549)	$ 145		(8,921)	$ (175)
Net income attributable to Retail Opportunity Investments Corp.	48,844				48,844
Net income attributable to non-controlling interests	4,839							4,839
Other comprehensive income (loss)	$ (7,693)						(7,693)
Total (in shares)	113,992,837		116,496,016
Balance (in shares) at Dec. 31, 2019	116,496,016		116,496,016
Balance at Dec. 31, 2019	$ 1,291,828		$ 12	$ 1,481,466	$ (297,998)		$ (4,132)	$ 112,480
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total (in shares)	116,496,016		116,496,016