Lapse in period of restricted shares issued under plans.

No definition available.

Name:	pgti_LapseInPeriodOfRestrictedSharesIssuedUnderPlans
Namespace Prefix:	pgti_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of non-management members.

+ References

No definition available.

+ Details

Name:	pgti_NumberOfNonManagementMembers
Namespace Prefix:	pgti_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share-based payment award, percentage of shares Issuable based on target performance.

+ References

No definition available.

+ Details

Name:	pgti_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfSharesIssuableBasedOnTargetPerformance
Namespace Prefix:	pgti_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award performance percentage.

+ References

No definition available.

+ Details

Name:	pgti_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePercentage
Namespace Prefix:	pgti_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Amount of deferred tax expense from write-off of the deferred tax asset related to deductible stock options at exercise.

+ References

No definition available.

+ Details

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

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

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

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

+ Details

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

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

+ Details

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

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Description of terms of award under share-based payment arrangement.

+ References

+ Details

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

- Definition

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted average grant-date fair value of non-vested options outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of options vested.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of share options (or share units) exercised during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SellingGeneralAndAdministrativeExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=pgti_NewSouthWindowSolutionsLLCAndNewSouthWindowSolutionsOrlandoLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=pgti_SellerOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=pgti_SellerTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=pgti_SellerThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=pgti_EightNonEmployeeBoardMembersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=pgti_SpecialEmployeeGrantsOfCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pgti_TwoThousandAndNineteenEquityAndIncentiveCompensationPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=pgti_DirectorsExecutivesAndNonexecutiveEmployeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pgti_TwoThousandAndFourteenOmnibusIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pgti_TwoThousandSixEquityIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pgti_TwoThousandAndTwentyLongTermIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=pgti_FixedCriteriaMember
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:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=pgti_CompanyPerformanceCriteriaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pgti_TwoThousandAndNineteenLongTermIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands						1 Months Ended	12 Months Ended
	May 21, 2020 Member $ / shares shares	Feb. 14, 2020 $ / shares shares	Feb. 01, 2020 $ / shares shares	Feb. 14, 2019 shares	Mar. 28, 2014 shares	Jun. 30, 2020 shares	Jan. 02, 2021 USD ($) $ / shares shares	Dec. 28, 2019 USD ($) $ / shares shares	Dec. 29, 2018 USD ($) shares	May 22, 2019 shares	May 07, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued in employee grant, Shares									28,160
Compensation expense for stock based awards \| $							$ 5,458	$ 3,923	$ 3,383
Outstanding Intrinsic Value \| $							1,241
Exercisable options intrinsic value \| $							1,241
Aggregate intrinsic value of stock options exercised \| $							$ 3,400	$ 8,800	$ 20,300
Number of shares exercised							284,353	682,931	1,119,247
Proceeds from exercise of stock options \| $							$ 572	$ 1,562	$ 2,239
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for stock based awards \| $							$ 4,800	$ 3,200	3,400
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards	42,360						650,470
Weighted-average period							1 year 7 months 6 days
Restricted stock awards, forfeited							303,240
Performance criteria defined in share awards							The percentages, ranging from less than 80% to greater than 120% of the target amount of that EBIT metric, provide for the awarding of shares ranging from 0% to 150% of the target amount of shares with respect to half of the 305,030 shares, or 152,515 shares.
Weighted average fair value of common stock \| $ / shares							$ 16.48	$ 14.26
Number of non management board members \| Member	8
Weighted average fair value of common stock \| $ / shares	$ 13.41						$ 14.94
Total unrecognized compensation \| $							$ 6,700
Restricted Stock [Member] \| New South Window Solutions LLC and New South Window Solutions of Orlando LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards			258,064
Weighted average fair value of common stock \| $ / shares			$ 15.50
Weighted-average period			3 years
Restricted stock awards, forfeited						129,032
Restricted Stock [Member] \| Seller One [Member] \| New South Window Solutions LLC and New South Window Solutions of Orlando LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards			129,032
Restricted Stock [Member] \| Seller Two [Member] \| New South Window Solutions LLC and New South Window Solutions of Orlando LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards			64,516
Restricted Stock [Member] \| Seller Three [Member] \| New South Window Solutions LLC and New South Window Solutions of Orlando LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards			64,516
Restricted Stock [Member] \| Eight Non-Employee Board Members [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Lapsing period of restrictions related to restricted stock issued	1 year
Special Employee Grants of Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for stock based awards \| $									587
Special Employee Grants of Common Stock [Member] \| Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for stock based awards \| $									587
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Intrinsic Value \| $								$ 4,500	14,000
Exercisable options intrinsic value \| $								4,500	14,000
Stock options vested							0
Total fair value of options vested \| $								21	21
Proceeds from exercise of stock options \| $							$ 600	1,600	2,200
Tax benefit realized \| $							$ 800	$ 2,100	$ 5,200
2019 Equity and Incentive Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares available for grant							765,738			1,550,000
Common stock issued in employee grant, Shares							0
2019 Equity and Incentive Compensation Plan [Member] \| Restricted Stock [Member] \| Executives and Non-Executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards							650,470
Weighted average fair value of common stock \| $ / shares							$ 16.09
2014 Omnibus Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares available for grant							0				1,500,000
2006 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares available for grant					0
Common stock issued in employee grant, Shares					0
2020 Long-Term Incentive Plan [Member] \| Executives and Non-Executive Employees [Member] \| Fixed Criteria [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards		152,515
2020 Long-Term Incentive Plan [Member] \| Restricted Stock [Member] \| Executives and Non-Executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards		305,030
Weighted average fair value of common stock \| $ / shares		$ 16.56
2020 Long-Term Incentive Plan [Member] \| Restricted Stock [Member] \| Executives and Non-Executive Employees [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance percentage		80.00%
Percentage of shares issuable based on target performance		0.00%
2020 Long-Term Incentive Plan [Member] \| Restricted Stock [Member] \| Executives and Non-Executive Employees [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance percentage		120.00%
Percentage of shares issuable based on target performance		150.00%
2020 Long-Term Incentive Plan [Member] \| Company Performance Criteria [Member] \| Executives and Non-Executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards		152,515
2019 Long-Term Incentive Plan [Member] \| Restricted Stock [Member] \| Executives and Non-Executive Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards				258,628
2019 Long-Term Incentive Plan [Member] \| Company Performance Criteria [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards								0
Restricted stock awards, forfeited				107,683