Receivables - Narrative (Detail) $ in Millions	9 Months Ended
	Sep. 26, 2020 USD ($) portfolioSegment	Jun. 27, 2020 USD ($)	Dec. 28, 2019 USD ($)	Sep. 28, 2019 USD ($)	Jun. 29, 2019 USD ($)	Dec. 29, 2018 USD ($)
Financing Receivable, Past Due [Line Items]
Increase in allowance for credit losses			$ 67.5
Minimum payment term for trade and other accounts receivable (in days)	30 days
Maximum payment term for trade and other accounts receivable (in days)	120 days
Average payment term for finance receivables (in years)	4 years
Maximum payment term for contract receivables (in years)	10 years
Number of portfolio segments | portfolioSegment	2
Minimum period past due to consider receivable balances as delinquent (in days)	30 days
Minimum period past due to declare receivable as non-accrual status (in days)	90 days
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
Financing Receivable, Past Due [Line Items]
Increase in allowance for credit losses			8.1
Finance Receivables
Financing Receivable, Past Due [Line Items]
Increase in allowance for credit losses	$ 75.0	$ 72.5	61.9	$ 61.1	$ 60.9	$ 61.4
Financing receivable, threshold period past due, writeoff (in days)	120 days
Financing receivable, threshold period after asset repossession, writeoff (in days)	60 days
Contract Receivables
Financing Receivable, Past Due [Line Items]
Increase in allowance for credit losses	$ 9.0	$ 9.1	$ 5.6	$ 6.0	$ 5.0	$ 4.3
Contract Receivables | Non-Franchisee
Financing Receivable, Past Due [Line Items]
Financing receivable, threshold period past due, writeoff (in days)	150 days
Contract Receivables | Franchisee
Financing Receivable, Past Due [Line Items]
Financing receivable, threshold period past due, writeoff (in days)	180 days
Financing Receivables And Contract Receivables, Customer Bankruptcy
Financing Receivable, Past Due [Line Items]
Financing receivable, threshold period past due, writeoff (in days)	180 days