Note 15 - Segment Information - Industry Segment (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Revenue		$ 604,882	$ 303,222	$ 1,141,036	$ 633,982
Adjusted EBITDA(a)	[1]	216,339	84,417	385,569	191,132
Assets, Total		2,720,486	2,557,931	2,720,486	2,557,931	$ 2,573,517
Depreciation, Depletion and Amortization		57,880	52,199	113,834	112,096
Capital Expenditures		39,418	43,655	76,061	57,455
Coal Revenue [Member]
Revenue		532,692	259,832	1,009,060	545,367
Terminal Revenue [Member]
Revenue		21,779	17,380	43,176	35,592
Freight Revenue [Member]
Revenue		50,411	26,010	88,800	53,023
Intersegment Eliminations [Member]
Revenue		0	0	0	0
Adjusted EBITDA(a)	[1]	0	0	0	0
Assets, Total		0	0	0	0
Depreciation, Depletion and Amortization		0	0	0	0
Capital Expenditures		0	0	0	0
Intersegment Eliminations [Member] | Coal Revenue [Member]
Revenue		0	0	0	0
Intersegment Eliminations [Member] | Terminal Revenue [Member]
Revenue		0	0	0	0
Intersegment Eliminations [Member] | Freight Revenue [Member]
Revenue		0	0	0	0
Pennsylvania Mining Complex [Member]
Adjusted EBITDA(a)		203,980	78,267	362,239	177,451
Depreciation, Depletion and Amortization		49,465	50,169	100,421	104,950
Pennsylvania Mining Complex [Member] | Operating Segments [Member]
Revenue		566,328	284,492	1,077,678	595,971
Adjusted EBITDA(a)	[1]	203,980	78,267	362,239	177,451
Assets, Total		1,735,635	1,799,848	1,735,635	1,799,848
Depreciation, Depletion and Amortization		49,465	50,169	100,421	104,950
Capital Expenditures		21,673	39,874	34,651	52,453
Pennsylvania Mining Complex [Member] | Operating Segments [Member] | Coal Revenue [Member]
Revenue		518,942	258,482	991,903	542,948
Pennsylvania Mining Complex [Member] | Operating Segments [Member] | Terminal Revenue [Member]
Revenue		0	0	0	0
Pennsylvania Mining Complex [Member] | Operating Segments [Member] | Freight Revenue [Member]
Revenue		47,386	26,010	85,775	53,023
CONSOL Marine Terminal [Member]
Adjusted EBITDA(a)		15,077	10,965	29,554	22,926
Depreciation, Depletion and Amortization		1,142	1,200	2,307	2,414
CONSOL Marine Terminal [Member] | Operating Segments [Member]
Revenue		21,779	17,380	43,176	35,592
Adjusted EBITDA(a)	[1]	15,077	10,965	29,554	22,926
Assets, Total		80,238	104,848	80,238	104,848
Depreciation, Depletion and Amortization		1,142	1,200	2,307	2,414
Capital Expenditures		188	52	360	112
CONSOL Marine Terminal [Member] | Operating Segments [Member] | Coal Revenue [Member]
Revenue		0	0	0	0
CONSOL Marine Terminal [Member] | Operating Segments [Member] | Terminal Revenue [Member]
Revenue		21,779	17,380	43,176	35,592
CONSOL Marine Terminal [Member] | Operating Segments [Member] | Freight Revenue [Member]
Revenue		0	0	0	0
Other Segments [Member]
Adjusted EBITDA(a)		(2,718)	(4,815)	(6,224)	(9,245)
Depreciation, Depletion and Amortization		7,273	830	11,106	4,732
Other Segments [Member] | Operating Segments [Member]
Revenue		16,775	1,350	20,182	2,419
Adjusted EBITDA(a)	[1]	(2,718)	(4,815)	(6,224)	(9,245)
Assets, Total		904,613	653,235	904,613	653,235
Depreciation, Depletion and Amortization		7,273	830	11,106	4,732
Capital Expenditures		17,557	3,729	41,050	4,890
Other Segments [Member] | Operating Segments [Member] | Coal Revenue [Member]
Revenue		13,750	1,350	17,157	2,419
Other Segments [Member] | Operating Segments [Member] | Terminal Revenue [Member]
Revenue		0	0	0	0
Other Segments [Member] | Operating Segments [Member] | Freight Revenue [Member]
Revenue		$ 3,025	$ 0	$ 3,025	$ 0

[1] Refer to “Reconciliation of Segment Information to Consolidated Amounts” for the reconciliation of Adjusted EBITDA, a non-GAAP measure, to its most directly comparable GAAP measure.