Finance Receivables (Aging Of Past Due Finance Receivables Including Non-Accrual Status Finance Receivables) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 6,785,813	$ 6,818,368
Total Past Due	222,988	196,963
Total finance receivables	7,008,801	7,015,331	$ 6,560,245	$ 6,110,256	$ 5,889,519
31-60 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	132,302	119,884
61-90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	49,961	44,210
Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	40,725	32,869
Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	5,760,818	5,796,003
Total Past Due	221,393	195,468
Total finance receivables	5,982,211	5,991,471	5,607,924	5,265,044	5,073,115
Retail | 31-60 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	131,302	118,996
Retail | 61-90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	49,642	43,680
Retail | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	40,449	32,792
Wholesale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,024,995	1,022,365
Total Past Due	1,595	1,495
Total finance receivables	1,026,590	1,023,860	$ 952,321	$ 845,212	$ 816,404
Wholesale | 31-60 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,000	888
Wholesale | 61-90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	319	530
Wholesale | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 276	$ 77