(Guarantor Subsidiaries, Condensed Statement of Cash Flows) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	$ 248,110	$ 329,107	$ 291,693
Cash Flows from Investing Activities:
Capital Expenditures	(81,413)	(53,600)	(143,053)
Proceeds from Sales of Assets	24,582	7,842	12,779
Net Cash Used in Investing Activities	(56,831)	(45,758)	(130,274)
Cash Flows from Financing Activities:
(Payments on) Proceeds from Miscellaneous Borrowings	(3,904)	431	(5,829)
Affiliated Credit Facility	0		0
Net (Payments on) Proceeds from Revolver - MLP	(201,000)	16,000	185,000
Distributions to Noncontrolling Interest	(21,892)	(21,657)	(5,060)
Distribution of Proceeds			0
Distributions to Noncontrolling Interest	(21,892)	(21,657)
Proceeds from Sale of MLP Interest	0	0	148,359
Units/Shares Withheld for Taxes	(2,156)	0	0
Intercompany Contributions/(Distributions)	0	0	0
Change in Parent Net Investment	(156,502)	(270,969)	(461,051)
Spin Distribution to CNX Resources	(425,000)	0	0
Debt Issuance and Financing Fees	(32,304)	(482)	(16,336)
Net Cash (Used in) Provided by Financing Activities	(50,611)	(276,677)	(154,917)
Elimination
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	0	0	0
Cash Flows from Investing Activities:
Capital Expenditures	0	0	0
Proceeds from Sales of Assets	0	0	0
Net Cash Used in Investing Activities	0	0	0
Cash Flows from Financing Activities:
(Payments on) Proceeds from Miscellaneous Borrowings	0	0	0
Affiliated Credit Facility	(196,583)		0
Net (Payments on) Proceeds from Revolver - MLP	0	0	0
Distributions to Noncontrolling Interest			11,353
Distribution of Proceeds			0
Distributions to Noncontrolling Interest	34,508	42,634
Proceeds from Sale of MLP Interest			0
Units/Shares Withheld for Taxes	0
Intercompany Contributions/(Distributions)	162,075	0	0
Change in Parent Net Investment	0	0	0
Spin Distribution to CNX Resources	0
Debt Issuance and Financing Fees	0	0	0
Net Cash (Used in) Provided by Financing Activities	0	42,634	11,353
Parent Issuer | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	(17,032)	253	12,608
Cash Flows from Investing Activities:
Capital Expenditures	0	0	0
Proceeds from Sales of Assets	0	0	0
Net Cash Used in Investing Activities	0	0	0
Cash Flows from Financing Activities:
(Payments on) Proceeds from Miscellaneous Borrowings	(3,503)	231	(600)
Affiliated Credit Facility	0		0
Net (Payments on) Proceeds from Revolver - MLP	0	0	0
Distributions to Noncontrolling Interest			0
Distribution of Proceeds			0
Distributions to Noncontrolling Interest	0	0
Proceeds from Sale of MLP Interest			0
Units/Shares Withheld for Taxes	0
Intercompany Contributions/(Distributions)	(5,573)	270,969	461,051
Change in Parent Net Investment	(156,502)	(270,969)	(461,051)
Spin Distribution to CNX Resources	(425,000)
Debt Issuance and Financing Fees	(32,304)	(482)	(12,007)
Net Cash (Used in) Provided by Financing Activities	169,265	(251)	(12,607)
Guarantor | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	192,423	255,756	202,177
Cash Flows from Investing Activities:
Capital Expenditures	(61,917)	(40,896)	(108,980)
Proceeds from Sales of Assets	23,082	7,819	12,708
Net Cash Used in Investing Activities	(38,835)	(33,077)	(96,272)
Cash Flows from Financing Activities:
(Payments on) Proceeds from Miscellaneous Borrowings	(305)	279	(5,176)
Affiliated Credit Facility	0		(6,039)
Net (Payments on) Proceeds from Revolver - MLP	0	0	0
Distributions to Noncontrolling Interest			(5,060)
Distribution of Proceeds			342,711
Distributions to Noncontrolling Interest	0	(21,657)
Proceeds from Sale of MLP Interest			0
Units/Shares Withheld for Taxes	(171)
Intercompany Contributions/(Distributions)	(156,502)	(270,969)	(461,051)
Change in Parent Net Investment	0	0	17,328
Spin Distribution to CNX Resources	0
Debt Issuance and Financing Fees	0	0	0
Net Cash (Used in) Provided by Financing Activities	(156,978)	(292,347)	(117,287)
Non-Guarantor | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	75	0	0
Cash Flows from Investing Activities:
Capital Expenditures	0	0	0
Proceeds from Sales of Assets	0	0	0
Net Cash Used in Investing Activities	0	0	0
Cash Flows from Financing Activities:
(Payments on) Proceeds from Miscellaneous Borrowings	0	0	0
Affiliated Credit Facility	0		0
Net (Payments on) Proceeds from Revolver - MLP	0	0	0
Distributions to Noncontrolling Interest			0
Distribution of Proceeds			0
Distributions to Noncontrolling Interest	0	0
Proceeds from Sale of MLP Interest			0
Units/Shares Withheld for Taxes	0
Intercompany Contributions/(Distributions)		0	0
Change in Parent Net Investment	0	0	0
Spin Distribution to CNX Resources	0
Debt Issuance and Financing Fees	0	0	0
Net Cash (Used in) Provided by Financing Activities	0	0	0
CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	72,644	73,098	76,908
Cash Flows from Investing Activities:
Capital Expenditures	(19,496)	(12,704)	(34,073)
Proceeds from Sales of Assets	1,500	23	71
Net Cash Used in Investing Activities	(17,996)	(12,681)	(34,002)
Cash Flows from Financing Activities:
(Payments on) Proceeds from Miscellaneous Borrowings	(96)	(79)	(53)
Affiliated Credit Facility	196,583		6,039
Net (Payments on) Proceeds from Revolver - MLP	(201,000)	16,000	185,000
Distributions to Noncontrolling Interest			(11,353)
Distribution of Proceeds			(342,711)
Distributions to Noncontrolling Interest	(56,400)	(42,634)
Proceeds from Sale of MLP Interest			148,359
Units/Shares Withheld for Taxes	(1,985)
Intercompany Contributions/(Distributions)		0	0
Change in Parent Net Investment	0	0	(17,328)
Spin Distribution to CNX Resources	0
Debt Issuance and Financing Fees	0	0	(4,329)
Net Cash (Used in) Provided by Financing Activities	(62,898)	(26,713)	(36,376)
Term Loan A
Cash Flows from Financing Activities:
Proceeds from issuance of debt	100,000	0	0
Term Loan A | Elimination
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan A | Parent Issuer | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	100,000
Term Loan A | Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan A | Non-Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan A | CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan B
Cash Flows from Financing Activities:
Proceeds from issuance of debt	392,147	0	0
Term Loan B | Elimination
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan B | Parent Issuer | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	392,147
Term Loan B | Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan B | Non-Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Term Loan B | CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Senior Secured Second Lien Notes due 2025
Cash Flows from Financing Activities:
Proceeds from issuance of debt	300,000	$ 0	$ 0
Senior Secured Second Lien Notes due 2025 | Elimination
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Senior Secured Second Lien Notes due 2025 | Parent Issuer | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	300,000
Senior Secured Second Lien Notes due 2025 | Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Senior Secured Second Lien Notes due 2025 | Non-Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	0
Senior Secured Second Lien Notes due 2025 | CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Cash Flows from Financing Activities:
Proceeds from issuance of debt	$ 0