Finance Receivables (Investment Of Wholesale Finance Receivables By Internal And External Credit Quality Indicator) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	$ 7,411,816	$ 7,157,557	$ 7,008,801	$ 7,015,331	$ 6,560,245
Retail
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	6,328,201	6,140,600	5,982,211	5,991,471	5,607,924
Retail | Prime
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	5,183,754	4,966,193
Retail | Sub-prime
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	1,144,447	1,174,407
Wholesale
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	1,083,615	1,016,957	$ 1,026,590	$ 1,023,860	$ 952,321
Wholesale | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	2,210	688
Wholesale | Substandard
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	9,660	3,837
Wholesale | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	10,299	26,866
Wholesale | Medium Risk
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	25,802	9,917
Wholesale | Low Risk
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, gross	$ 1,035,644	$ 975,649