Name:	sncy_CaresActEmployeeRetentionCredit
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of grants provided under CARES Act, recognized during period.

No definition available.

Name:	sncy_CaresActGrantsRecognized
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of charges relating to contractual obligations for retired technology.

No definition available.

Name:	sncy_ContractualObligationForRetiredTechnologyCharges
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of early out payments and other outsourcing expenses incurred during the period.

No definition available.

Name:	sncy_EarlyOutPaymentsAndOtherOutsourcingExpenses
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of gain on reward program modifications such as, accelerated loyalty point expiration, while making points more valuable for its members.

No definition available.

Name:	sncy_GainOnRewardProgramModifications
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of gain on sale of airport slot rights.

No definition available.

Name:	sncy_GainOnSaleOfAirportSlotRights
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of net loss results from the carrying value exceeding the fair value at time of purchase.

No definition available.

Name:	sncy_NetLossOnPurchaseOfAircrafts
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of other expenses incurred relating to special items.

No definition available.

Name:	sncy_SpecialItemsOther
Namespace Prefix:	sncy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

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

Indicates designation of financial information when substantially all business or separately identifiable line of business transfers from one entity to another entity. Acceptable values are "Predecessor" and "Successor".

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 45
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=116635682&loc=SL2890601-112764

Name:	us-gaap_FinancialDesignationPredecessorAndSuccessorFixedList
Namespace Prefix:	us-gaap_
Data Type:	us-types:financialDesignationType
Balance Type:	na
Period Type:	duration

Amount of (gain) loss for an event or transaction that is unusual in nature or occurs infrequently, or both.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109227538&loc=d3e44648-109337

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=114868879&loc=SL114871939-224231

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=114868883&loc=SL114871943-224233

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599