Note 11 - Noncontrolling Interests (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended			12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	[1]	Dec. 31, 2017
Payments to Noncontrolling Interests	$ 3,400
Adjustments to Additional Paid in Capital, Other	1,200
Noncontrolling Interest, Change in Redemption Value	3,918
KIM Lincoln, LLC [Member]
Ownership Interest in Joint Venture, Percentage				90.00%
Lincoln Square Property, LP [Member]
Ownership Interest in Joint Venture, Percentage				10.00%
Noncontrolling Interest [Member]
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	$ 4,600
Preferred A Units [Member]
Non-controlling Interest, Units Redeemed				79,642,697
Payments for Repurchase of Redeemable Noncontrolling Interest				$ 79,900
Payments for Repurchase of Redeemable Noncontrolling Interest, Accrued Preferred Return				$ 400
Non-controlling Interest, Par Value				$ 1
Non-controlling Interest, Annual Return				5.00%

[1] During 2017, KIM Lincoln, a wholly owned subsidiary of the Company, and Lincoln Member entered into a joint venture agreement wherein KIM Lincoln has a 90% controlling interest and Lincoln Member has a 10% noncontrolling interest. During the nine months ended September 30, 2018, the Company recorded an adjustment of $3.9 million to the estimated redemption fair market value of this noncontrolling interest in accordance with the provisions of the joint venture agreement and ASC 480 - Accounting for Redeemable Equity Instruments.