Finance Receivables - Aging Of Past Due Finance Receivables Including Non-Accrual Status Finance Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Past Due [Line Items]
Total financing receivables	$ 6,911,300	$ 6,833,944	$ 7,572,947	$ 7,411,816	$ 7,157,557
Current
Financing Receivable, Past Due [Line Items]
Total financing receivables	6,716,205	6,653,925
Total Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	195,095	180,019
31-60 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	115,951	106,984
61-90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	44,327	39,956
Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	34,817	33,079
Retail
Financing Receivable, Past Due [Line Items]
Total financing receivables	6,493,519	6,344,195	6,416,428	6,328,201	6,140,600
Retail | Current
Financing Receivable, Past Due [Line Items]
Total financing receivables	6,298,485	6,164,369
Retail | Total Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	195,034	179,826
Retail | 31-60 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	115,942	106,818
Retail | 61-90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	44,326	39,933
Retail | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	34,766	33,075
Wholesale
Financing Receivable, Past Due [Line Items]
Total financing receivables	417,781	489,749	$ 1,156,519	$ 1,083,615	$ 1,016,957
Wholesale | Current
Financing Receivable, Past Due [Line Items]
Total financing receivables	417,720	489,556
Wholesale | Total Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	61	193
Wholesale | 31-60 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	9	166
Wholesale | 61-90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	1	23
Wholesale | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total financing receivables	$ 51	$ 4