ADDITIONAL INFORMATION WITH RESPECT TO UNRESTRICTED SUBSIDIARIES - Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Current Assets:
Cash and Cash Equivalents	$ 78,166	$ 80,293
Restricted Cash	661	0
Trade Receivables, net of Allowance	113,098	131,688
Other Receivables, net of Allowance	33,878	40,984
Inventories	58,638	54,131
Prepaid Expenses and Other Assets	26,302	30,933
Total Current Assets	310,743	338,029
Property, Plant and Equipment:
Property, Plant and Equipment	5,053,698	5,008,180
Less—Accumulated Depreciation, Depletion and Amortization	2,965,903	2,916,015
Total Property, Plant and Equipment—Net	2,087,795	2,092,165
Other Assets:
Deferred Income Taxes	102,425	103,505
Right of Use Asset - Operating Leases	67,787	72,632
Other, net of Allowance	84,718	87,471
Total Other Assets	254,930	263,608
TOTAL ASSETS	2,653,468	2,693,802	$ 2,767,041
Current Liabilities:
Accounts Payable	89,556	106,223
Accounts (Recoverable) Payable - Related Parties	0	0
Current Portion of Long-Term Debt	67,441	50,272
Other Accrued Liabilities	237,261	235,769
Total Current Liabilities	394,258	392,264
Long-Term Debt:
Long-Term Debt	604,927	653,802
Finance Lease Obligations	21,942	9,036
Total Long-Term Debt	626,869	662,838
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	429,085	432,496
Pneumoconiosis Benefits	201,718	202,142
Asset Retirement Obligations	254,805	250,211
Workers’ Compensation	60,961	61,194
Salary Retirement	44,439	49,930
Operating Lease Liability	52,975	55,413
Other	17,268	14,919
Total Deferred Credits and Other Liabilities	1,061,251	1,066,305
TOTAL LIABILITIES	2,082,378	2,121,407
Total CONSOL Energy Inc. Stockholders’ Equity	439,405	435,199
Noncontrolling Interest	131,685	137,196
TOTAL LIABILITIES AND EQUITY	2,653,468	2,693,802
Company and Restricted Subsidiaries
Current Assets:
Cash and Cash Equivalents	77,896	79,717
Restricted Cash	0
Trade Receivables, net of Allowance	0	0
Other Receivables, net of Allowance	31,654	39,412
Inventories	44,852	41,478
Prepaid Expenses and Other Assets	21,931	25,181
Total Current Assets	176,333	185,788
Property, Plant and Equipment:
Property, Plant and Equipment	4,059,878	4,023,282
Less—Accumulated Depreciation, Depletion and Amortization	2,382,961	2,344,777
Total Property, Plant and Equipment—Net	1,676,917	1,678,505
Other Assets:
Deferred Income Taxes	102,425	103,505
Right of Use Asset - Operating Leases	53,268	56,937
Other, net of Allowance	71,277	74,015
Total Other Assets	226,970	234,457
TOTAL ASSETS	2,080,220	2,098,750
Current Liabilities:
Accounts Payable	65,078	79,140
Accounts (Recoverable) Payable - Related Parties	(4,279)	(1,419)
Current Portion of Long-Term Debt	58,529	45,020
Other Accrued Liabilities	197,677	196,314
Total Current Liabilities	317,005	319,055
Long-Term Debt:
Long-Term Debt	452,472	505,646
Finance Lease Obligations	16,867	7,391
Total Long-Term Debt	469,339	513,037
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	429,085	432,496
Pneumoconiosis Benefits	195,449	196,114
Asset Retirement Obligations	243,837	239,410
Workers’ Compensation	57,313	57,583
Salary Retirement	44,439	49,930
Operating Lease Liability	42,039	43,906
Other	16,445	14,134
Total Deferred Credits and Other Liabilities	1,028,607	1,033,573
TOTAL LIABILITIES	1,814,951	1,865,665
Total CONSOL Energy Inc. Stockholders’ Equity	133,584	95,889
Noncontrolling Interest	131,685	137,196
TOTAL LIABILITIES AND EQUITY	2,080,220	2,098,750
Unrestricted Subsidiaries
Current Assets:
Cash and Cash Equivalents	270	576
Restricted Cash	661
Trade Receivables, net of Allowance	113,098	131,688
Other Receivables, net of Allowance	2,224	1,572
Inventories	13,786	12,653
Prepaid Expenses and Other Assets	4,371	5,752
Total Current Assets	134,410	152,241
Property, Plant and Equipment:
Property, Plant and Equipment	993,820	984,898
Less—Accumulated Depreciation, Depletion and Amortization	582,942	571,238
Total Property, Plant and Equipment—Net	410,878	413,660
Other Assets:
Deferred Income Taxes	0	0
Right of Use Asset - Operating Leases	14,519	15,695
Other, net of Allowance	13,441	13,456
Total Other Assets	27,960	29,151
TOTAL ASSETS	573,248	595,052
Current Liabilities:
Accounts Payable	24,478	27,083
Accounts (Recoverable) Payable - Related Parties	4,279	1,419
Current Portion of Long-Term Debt	8,912	5,252
Other Accrued Liabilities	39,584	39,455
Total Current Liabilities	77,253	73,209
Long-Term Debt:
Long-Term Debt	152,455	148,156
Finance Lease Obligations	5,075	1,645
Total Long-Term Debt	157,530	149,801
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	6,269	6,028
Asset Retirement Obligations	10,968	10,801
Workers’ Compensation	3,648	3,611
Salary Retirement	0	0
Operating Lease Liability	10,936	11,507
Other	823	785
Total Deferred Credits and Other Liabilities	32,644	32,732
TOTAL LIABILITIES	267,427	255,742
Total CONSOL Energy Inc. Stockholders’ Equity	305,821	339,310
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	$ 573,248	$ 595,052