Deferred Compensation Plan, Interest Rate

No definition available.

Name:	frgi_DeferredCompensationPlanInterestRate
Namespace Prefix:	frgi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employer may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	frgi_DefinedContributionPlanEmployerMatchingContributionMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	frgi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Hours of Service Required

+ References

No definition available.

+ Details

Name:	frgi_DefinedContributionPlanHoursOfServiceRequired
Namespace Prefix:	frgi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Vesting Period for Employer Match

+ References

No definition available.

+ Details

Name:	frgi_DefinedContributionPlanVestingPeriodForEmployerMatch
Namespace Prefix:	frgi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_DefinedContributionPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

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

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=frgi_FiestaCorporationRetirementSavingsPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=frgi_FirstTrancheMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=frgi_SecondTrancheMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Retirement Plans (Details) $ in Millions	12 Months Ended
Retirement Plans (Details) $ in Millions	Jan. 02, 2022 USD ($) hour	Jan. 03, 2021 USD ($)	Dec. 29, 2019 USD ($)
Maximum
Defined Contribution Plan Disclosure [Line Items]
Vesting period for employer match	5 years		5 years
Minimum
Defined Contribution Plan Disclosure [Line Items]
Vesting period for employer match	1 year		1 year
Required hours of service \| hour	1,000
401K \| Retirement Plan
Defined Contribution Plan Disclosure [Line Items]
Maximum employer contribution, percentage of eligible employee compensation	3.00%		3.00%
Maximum annual contribution per employee, percent	50.00%
Retirement Plan employer matching expense	$ 0.2	$ 0.2	$ 0.3
Interest rate that can be earned by deferred amounts	8.00%
Deferred compensation, current and non-current	$ 0.3	$ 0.5
401K \| Retirement Plan \| Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match	50.00%		50.00%
Employer matching contribution, percentage of employee compensation	6.00%		6.00%
401K \| Retirement Plan \| First Tranche [Member] \| Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percentage of employee compensation	3.00%
401K \| Retirement Plan \| Second Tranche [Member] \| Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match	50.00%
Employer matching contribution, percentage of employee compensation	2.00%