LONG-TERM DEBT - Narrative (Details) $ / shares in Units, $ in Thousands		3 Months Ended		12 Months Ended
	Dec. 15, 2025 USD ($) $ / shares shares	Mar. 31, 2026 USD ($)	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2020 USD ($) day $ / shares	Apr. 30, 2020
Debt Instrument [Line Items]
Long-term debt, gross		$ 2,366,853		$ 2,421,359
Loss on debt extinguishment		12,009	$ 0
Proceeds from issuance of convertible senior notes						$ 334,650
Capped Call Transaction
Debt Instrument [Line Items]
Cost incurred in connection with capped calls						$ 35,673
Minimum \| Call Option \| Capped Call Transaction
Debt Instrument [Line Items]
Strike price (in usd per share) \| $ / shares						$ 12.84
Maximum \| Call Option \| Capped Call Transaction
Debt Instrument [Line Items]
Strike price (in usd per share) \| $ / shares						$ 18.19
Convertible Notes
Debt Instrument [Line Items]
Purchase of outstanding debt					$ 14,346
Senior Notes due March 2034
Debt Instrument [Line Items]
Long-term debt, gross		$ 500,000		0
Stated rate, debt instrument		5.875%
Debt instrument, price, percentage of par		10000.00%
Senior Notes due January 2029
Debt Instrument [Line Items]
Long-term debt, gross		$ 0		500,000
Stated rate, debt instrument		6.00%
Purchase and retirement of long term debt		$ 500,000
Loss on debt extinguishment		12,009
Convertible Senior Notes due 2026
Debt Instrument [Line Items]
Long-term debt, gross		$ 208,447		208,131
Stated rate, debt instrument		2.25%
Principal		$ 208,553		208,556
Convertible Senior Notes due 2026 \| Convertible Notes
Debt Instrument [Line Items]
Long-term debt, gross		208,447		208,131
Stated rate, debt instrument						2.25%	2.25%
Loss on debt extinguishment				842
Principal	$ 122,098	208,553		208,556		$ 345,000
Conversion price (in usd per share) \| $ / shares	$ 12.84
Additional cash consideration	$ 855
Conversion ratio (in shares)						77.8816
Debt issuance costs gross						$ 10,350
Convertible Senior Notes due 2026 \| Convertible Notes \| Common Stock
Debt Instrument [Line Items]
Issuance related to convertible debt (in shares) \| shares	9,509,188
Convertible Senior Notes due 2026 \| Convertible Notes \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Threshold percentage of stock price trigger						130.00%
Threshold trading days \| day						20
Threshold consecutive trading days \| day						30
Convertible Senior Notes due 2026 \| Convertible Notes \| Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Threshold percentage of stock price trigger						98.00%
Threshold trading days \| day						5
Threshold consecutive trading days \| day						10
Initial Notes - Convertible 7.25% Senior Notes Due 2032
Debt Instrument [Line Items]
Principal			400,000
Convertible 2.25% Senior Notes Due 2026, Additional Option To Initial Purchasers \| Convertible Notes
Debt Instrument [Line Items]
Principal						$ 45
Convertible 2.25% Senior Notes Due 2026, Liability Component \| Convertible Notes
Debt Instrument [Line Items]
Debt issuance costs gross						7,024
Convertible 2.25% Senior Notes Due 2026, Equity Component \| Convertible Notes
Debt Instrument [Line Items]
Debt issuance costs gross						$ 3,326
New Notes - Convertible 7.25% Senior Notes Due 2032
Debt Instrument [Line Items]
Principal			$ 200,000
Convertible 7.25% Senior Notes Due 2032
Debt Instrument [Line Items]
Long-term debt, gross		$ 595,049		$ 594,840
Stated rate, debt instrument		7.25%
Debt instrument, price, percentage of par			100.50%
Principal		$ 600,000
Underwriter discount and issuance costs			$ 1,500

CNX Resources Corp 10-Q