Supplemental Oil and Gas Disclosures (unaudited) - Oil and Gas, Change in Standardized Measure, Discounted Future Net Cash Flow (unaudited) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Oil and Gas, Standardized Measure, Discounted Future Net Cash Flow [Roll Forward]
Beginning balance	$ 633,086	$ 1,062,333	$ 6,993,602
Net change in sales and transfer prices and in production (lifting) costs related to future production	943,628	(272,270)	(5,386,961)
Changes in estimated future development costs	(37,067)	(2,933)	91,657
Sales and transfers of natural gas, NGLs, and oil produced during the period	(381,138)	(271,692)	(201,884)
Net change due to extensions, discoveries, and improved recoveries	75,400	18,261	36,107
Net change due to purchases (sales) of minerals in place	337,761	(90,531)
Net change due to revisions in quantity estimates	1,007,937	(74,031)	(3,058,900)
Previously estimated development costs incurred during the period	21,467	24,291	27,598
Net change in future income taxes	(404,531)	131,401	1,790,684
Accretion of discount	67,190	123,255	861,914
Changes in timing and other	80,931	(14,998)	(91,484)
Ending balance	$ 2,344,664	$ 633,086	$ 1,062,333

Oil and Gas, Standardized Measure, Discounted Future Net Cash Flow, Purchase (Sales) of Mineral in Place

No definition available.

Name:	bkv_OilAndGasStandardizedMeasureDiscountedFutureNetCashFlowPurchaseSalesOfMineralInPlace
Namespace Prefix:	bkv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of extensions, discoveries and improved recovery of proved oil and gas reserves.

+ References

+ Details

Name:	srt_ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of change in estimated future development costs.

+ References

+ Details

Name:	srt_IncreaseDecreaseInEstimatedFutureDevelopmentCosts
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of change in the estimated future income tax on future pretax net cash flows related to the entity's proved oil and gas reserves.

+ References

+ Details

Name:	srt_IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	srt_IncreaseDecreaseInStandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesRollForward
Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of change in sales and transfer prices and in production (lifting) costs related to future production.

+ References

+ Details

Name:	srt_NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase in standardized measure of discounted future net cash flow as a result of previously estimated development costs incurred.

+ References

+ Details

Name:	srt_PreviouslyEstimatedDevelopmentCostsIncurred
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of revisions of estimated quantity of oil and gas in proved reserves.

+ References

+ Details

Name:	srt_RevisionsOfPreviousQuantityEstimates
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of (increase) decrease in standardized measure of discounted future net cash flow as a result of sales and transfers of oil and gas produced.

+ References

+ Details

Name:	srt_SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of changes from other sources.

+ References

+ Details

Name:	srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesOther
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of accretion of discount for the standardized measure of discounted future net cash flow related to proved oil and gas reserves.

+ References

+ Details

Name:	srt_StandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesAccretionOfDiscount
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount, after discount, future accumulated cash outflow for development and production costs, and future income tax expense, of estimated future accumulated cash inflow for proved oil and gas reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Form 20-F
-Number Part II
-Section Item 18
-Subparagraph (Instruction 2)
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 55
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477916/932-235-55-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 35A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-35A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-33

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 29
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-29

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 35A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-35A

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-33

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-33

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 35A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-35A

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-31

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 35
-SubTopic 235
-Topic 932
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-35

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-SubTopic 235
-Topic 932
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-30

+ Details

Name:	srt_StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant