Subsequent Events (Details) $ / shares in Units, ft² in Thousands, $ in Millions						12 Months Ended
	Feb. 22, 2017 $ / shares	Jan. 31, 2017 shares	Jan. 25, 2017 USD ($) ft²	Jul. 12, 2016 shares	Aug. 10, 2015 shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2015 ft² $ / shares	Dec. 31, 2014 $ / shares
Subsequent Events (Details) [Line Items]
Equity redemption of OP Units (in shares)						755,762
Issuance of OP Units in connection with common stock (in shares)				6,555,000	5,520,000
Area of real estate property (in Square Feet) | ft²							1,300
Dividends per share (in dollars per share) | $ / shares						$ 0.72	$ 0.68	$ 0.64
Subsequent Event
Subsequent Events (Details) [Line Items]
Equity redemption of OP Units (in shares)		105,000
roic_RedeemableNoncontrollingInterestEquityRedemptionBasis		1
Issuance of OP Units in connection with common stock (in shares)		105,000
Dividends per share (in dollars per share) | $ / shares	$ 0.1875
Edmonds, Washington | PCC Edmonds | Subsequent Event
Subsequent Events (Details) [Line Items]
Consideration transferred | $			$ 8.6
Area of real estate property (in Square Feet) | ft²			34