Description of Business and Basis of Presentation - Initial Public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended			9 Months Ended
	Oct. 30, 2017	Dec. 30, 2017	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Class of Stock [Line Items]
Repayments of long-term debt					$ 6,236	$ 4,886
KKR
Class of Stock [Line Items]
Termination fees to related party			$ 220	$ 213	2,993	638
Berkshire
Class of Stock [Line Items]
Termination fees to related party			$ 52	$ 50	$ 156	$ 149
Forecast
Class of Stock [Line Items]
Extinguishment of debt		$ 353,300
Subsequent Event
Class of Stock [Line Items]
Transaction-related expenses expected during fourth quarter	$ 4,000
Component of proceeds from initial public offering to be used for general corporate purposes	11,800
Subsequent Event | KKR
Class of Stock [Line Items]
Termination fees to related party	$ 3,600
Ownership percentage in Company retained by equity sponsor	58.20%
Subsequent Event | Berkshire
Class of Stock [Line Items]
Termination fees to related party	$ 800
Ownership percentage in Company retained by equity sponsor	13.60%
Subsequent Event | Term Loan | First Lien Term Loans
Class of Stock [Line Items]
Repayments of long-term debt	$ 235,000
Subsequent Event | Term Loan | Second Lien Term Loans
Class of Stock [Line Items]
Repayments of long-term debt	$ 125,000
Subsequent Event | IPO
Class of Stock [Line Items]
Shares issued in initial public offering (shares)	18,170,000
Shares issued, offering price (in usd per share)	$ 22.00
Net proceeds from initial public offering	$ 375,800
Underwriting discounts and commissions	24,000
Subsequent Event | IPO | KKR
Class of Stock [Line Items]
Underwriting discounts and commissions	$ 700
Subsequent Event | Underwriter Option
Class of Stock [Line Items]
Shares issued in initial public offering (shares)	2,370,000