Debt - Schedule of redemption prices plus accrued and unpaid interest (Details) - Unsecured debt - Dollar Senior Note redemption price		12 Months Ended
	Feb. 09, 2018	Dec. 28, 2019
Debt Instrument, Redemption
Redemption price (percent)	103.00%
—2022
Debt Instrument, Redemption
Redemption price (percent)		103.125%
—2023
Debt Instrument, Redemption
Redemption price (percent)		101.563%
—2024 and thereafter
Debt Instrument, Redemption
Redemption price (percent)		100.00%