Note 4 - Common and Preferred Unit Distributions - Distributions Made to Partners (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended						3 Months Ended
		Mar. 31, 2024	[1]	Feb. 29, 2024	Mar. 31, 2023	[2]	Feb. 28, 2023	Mar. 31, 2024	Mar. 31, 2023
Distributions, common units								$ 42,186	$ 40,900
Preferred Partner [Member] | Preferred Stock [Member]
Distribution per unit, common units (in dollars per share)		$ 0		$ 30	$ 0		$ 30
Distribution, preferred stock		$ 0		$ 2,150	$ 0		$ 7,500
Preferred Partner [Member] | Preferred Stock [Member] | Distributions Covering January 1 - February 8, 2023 [Member]
Distribution per unit, common units (in dollars per share)	[3]						$ 12.33
Distribution, preferred stock	[3]						$ 586
Common Unitholders, General Partner [Member]
Distribution per unit, common units (in dollars per share)		$ 2.44		$ 0.75	$ 2.43		$ 0.75
Distributions, common units	[4]	$ 32,268		$ 9,918	$ 31,329		$ 9,571
Common Unitholders, General Partner [Member] | Distributions Covering January 1 - February 8, 2023 [Member]
Distribution per unit, common units (in dollars per share)	[3]						$ 0
Distributions, common units	[3],[4]						$ 0

[1] Special distribution was made to help cover unitholder tax liabilities associated with owning NRP's common units during 2023.

[2] Special distribution was made to help cover unitholder tax liabilities associated with owning NRP's common units during 2022.

[3] Relates to accrued distribution paid upon the redemption of 47,499 preferred units in February 2023.

[4] Totals include the amount paid to NRP's general partner in accordance with the general partner's 2% general partner interest.