Summary of Significant Accounting Policies - Fiscal Year and Business and Credit Concentrations (Details)	3 Months Ended	12 Months Ended
	Mar. 28, 2020	Dec. 28, 2019	Dec. 29, 2018
Fiscal Year
Number of weeks in each fiscal quarter		91 days	91 days
Number of weeks in fiscal period		364 days	364 days
Minimum
Fiscal Year
Number of years between 53 week fiscal years	5 years
Maximum
Fiscal Year
Number of weeks in fiscal period	371 days
Number of weeks in fourth fiscal quarter	98 days
Number of years between 53 week fiscal years	6 years