Document and Entity Information - shares	9 Months Ended
	Oct. 03, 2020	Oct. 31, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 03, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Trading Symbol	PGTI
Entity Registrant Name	PGT Innovations, Inc.
Entity Central Index Key	0001354327
Current Fiscal Year End Date	--01-02
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	001-37971
Entity Tax Identification Number	20-0634715
Entity Address, Address Line One	1070 Technology Drive
Entity Address, City or Town	North Venice
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	34275
City Area Code	941
Local Phone Number	480-1600
Entity Common Stock, Shares Outstanding		58,962,776
Title of 12(b) Security	Common stock, par value $0.01 per share
Security Exchange Name	NYSE
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false