Consolidated Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for credit losses on finance receivables	$ 390,936	$ 198,581	$ 189,885	$ 192,471	$ 173,343
Accounts receivable - Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	4,928	4,007	4,091
Provision charged to expense	853	1,569	731
Reserve adjustments	88	7	(137)
Write-offs, net of recoveries	(2,127)	(655)	(678)
Balance, end of period	3,742	4,928	4,007
Finance receivables - Allowance for credit losses
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	198,581	189,885	192,471
Provision charged to expense	181,870	134,536	106,870
Write-offs, net of recoveries	(90,119)	(125,840)	(109,456)
Allowance for credit losses on finance receivables	100,604	0	0
Balance, end of period	390,936	198,581	189,885
Inventories – allowance for obsolescence
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	49,349	39,015	38,669
Provision charged to expense	43,357	24,984	25,722
Reserve adjustments	718	(39)	(332)
Write-offs, net of recoveries	(21,429)	(14,611)	(25,044)
Balance, end of period	71,995	49,349	39,015
Deferred tax assets - Valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	29,024	21,868	21,561
Reserve adjustments	9,048	7,156	307
Balance, end of period	$ 38,072	$ 29,024	$ 21,868