Consolidated Statement of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Accumulated dividends in excess of earnings	Accumulated other comprehensive income	Non- controlling interests	Officer	Officer Accumulated dividends in excess of earnings
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]
Shares issued under the Equity Incentive Plan (in shares)		373,861
Shares issued under the Equity Incentive Plan	0		0
Shares withheld for employee taxes (in shares)		(70,168)
Shares withheld for employee taxes	(1,400)		(1,400)
Cancellation of restricted stock (in shares)		(4,999)
Stock based compensation expense	1,428		1,428
Adjustment to non-controlling interests ownership in Operating Partnership			(191)			191
Proceeds from the issuance of common stock (in shares)		75,314
Proceeds from the issuance of common stock	1,508		1,508
Registration expenditures	(48)		(48)
Cash dividends	(24,258)			(21,981)		(2,277)	$ (72)	$ (72)
Net income attributable to Retail Opportunity Investments Corp.	10,702			10,702
Net income attributable to non-controlling interests	1,122					1,122
Other comprehensive income (loss)	3,808				3,808
Balance (in shares) at Mar. 31, 2018		112,721,459
Balance at Mar. 31, 2018	$ 1,322,431	$ 11	1,413,887	(221,841)	5,664	124,710
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]
Shares issued under the Equity Incentive Plan (in shares)		445,022
Shares issued under the Equity Incentive Plan	0		0
Shares withheld for employee taxes (in shares)		(125,072)
Shares withheld for employee taxes	(1,986)		(1,986)
Cancellation of restricted stock (in shares)		(999)
Stock based compensation expense	1,651		1,651
Cash redemption for non-controlling interests	(1,246)					(1,246)
Adjustment to non-controlling interests ownership in Operating Partnership			56			(56)
Registration expenditures	(47)		(47)
Cash dividends	(24,766)			(22,519)		(2,247)	$ 142	$ 142
Net income attributable to Retail Opportunity Investments Corp.	13,250			13,250
Net income attributable to non-controlling interests	1,333					1,333
Other comprehensive income (loss)	$ (2,810)				(2,810)
Balance (in shares) at Mar. 31, 2019	114,311,788	114,311,788
Balance at Mar. 31, 2019	$ 1,293,949	$ 11	$ 1,440,754	$ (265,565)	$ 751	$ 117,998