Finance Receivables - Changes In Allowance For Credit Losses On Finance Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 411,015	$ 194,996	$ 198,581	$ 189,885
Provision for credit losses	7,835	33,747	178,433	94,621
Charge-offs	(22,820)	(41,076)	(107,894)	(121,538)
Recoveries	12,672	10,909	38,978	35,608
Balance, end of period	408,702	198,576	408,702	198,576
Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			100,604
Retail
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	389,758	186,722	188,501	182,098
Provision for credit losses	8,024	35,071	172,491	95,458
Charge-offs	(20,378)	(41,076)	(105,452)	(121,538)
Recoveries	12,672	10,909	38,978	35,608
Balance, end of period	390,076	191,626	390,076	191,626
Retail | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			95,558
Wholesale
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	21,257	8,274	10,080	7,787
Provision for credit losses	(189)	(1,324)	5,942	(837)
Charge-offs	(2,442)	0	(2,442)	0
Recoveries	0	0	0	0
Balance, end of period	$ 18,626	$ 6,950	18,626	$ 6,950
Wholesale | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			$ 5,046