Transactions with Affiliates - Narrative (Details) - USD ($)	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Related Party Transaction [Line Items]
General and administrative expense	$ 14,935,000	$ 12,671,000
Affiliated Entity
Related Party Transaction [Line Items]
General and administrative expense	0	100,000
Affiliated Entity \| Allocated Overhead Costs
Related Party Transaction [Line Items]
Due to (from) affiliates	100,000	(800,000)
Affiliated Entity \| Subordinated Debt Facility
Related Party Transaction [Line Items]
Subordinated debt facility allows us to draw advances	$ 1,000,000
Subordinated debt, interest rate on advances	5.00%
NuDevco Retail Holdings and NuDevco Retail
Related Party Transaction [Line Items]
Distributions to affiliates	$ 3,600,000	3,800,000
NuDevco Retail Holdings and NuDevco Retail \| Payment of Income Taxes Incurred by The Company
Related Party Transaction [Line Items]
Distributions to affiliates	$ 100,000	$ 2,700,000

Affiliate Costs, Due From Affiliates

No definition available.

Name:	spke_AffiliateCostsDueFromAffiliates
Namespace Prefix:	spke_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line Of Credit Facility, Maximum Amount Per Advance

+ References

No definition available.

+ Details

Name:	spke_LineOfCreditFacilityMaximumAmountPerAdvance
Namespace Prefix:	spke_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

+ Details

Name:	us-gaap_GeneralAndAdministrativeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The distributions of earnings to an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsOfDistributionsToAffiliates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=spke_AllocatedOverheadCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=spke_SubordinatedDebtFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=spke_NuDevcoRetailHoldingsandNuDevcoRetailMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=spke_PaymentofIncomeTaxesIncurredbytheCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: