Note 7 - Investments In and Advances to Real Estate Joint Ventures - Investment Details (Details) - USD ($)		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
The company's investment		$ 12,068,827,149	$ 11,929,276,453	$ 11,877,190,495	$ 12,653,444,998
Kim Pru and Kim Pru II [Member]
Average ownership interest	[1],[2]	15.00%
The company's investment	[1],[2]	$ 175,100,000	169,500,000
Kimco Income Fund [Member]
Average ownership interest	[2]	48.60%
The company's investment	[2]	$ 177,400,000	175,000,000.0
CPP [Member]
Average ownership interest	[2]	55.00%
The company's investment	[2]	$ 159,700,000	151,700,000
Other Joint Venture Programs [Member]
The company's investment		78,500,000	81,900,000
All Equity Method Investments [Member]
The company's investment	[3]	$ 590,700,000	$ 578,100,000

[1] Represents three separate joint ventures, with three separate accounts managed by Prudential Global Investment Management.

[2] The Company manages these joint venture investments and, where applicable, earns acquisition fees, leasing commissions, property management fees, asset management fees and construction management fees.

[3] Representing 97 property interests and 21.2 million square feet of GLA, as of December 31, 2020, and 98 property interests and 21.3 million square feet of GLA, as of December 31, 2019.