Finance Receivables - Changes In Allowance For Credit Losses On Finance Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 335,496	$ 190,872	$ 198,581	$ 189,885
Provision for credit losses	91,179	26,383	170,598	60,874
Charge-offs	(29,859)	(35,741)	(85,074)	(80,462)
Recoveries	14,199	13,482	26,306	24,699
Balance, end of period	411,015	194,996	411,015	194,996
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	311,368	181,426	188,501	182,098
Provision for credit losses	94,050	27,555	164,467	60,387
Charge-offs	(29,859)	(35,741)	(85,074)	(80,462)
Recoveries	14,199	13,482	26,306	24,699
Balance, end of period	389,758	186,722	389,758	186,722
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	24,128	9,446	10,080	7,787
Provision for credit losses	(2,871)	(1,172)	6,131	487
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Balance, end of period	$ 21,257	$ 8,274	21,257	$ 8,274
Wholesale | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			$ 5,046