Finance Receivables (Changes In The Allowance For Finance Credit Losses On Finance Receivables) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	$ 173,343	$ 147,178	$ 127,364
Provision for credit losses	132,444	136,617	101,345
Charge-offs	(160,972)	(148,566)	(123,911)
Recoveries	47,656	41,405	42,380
Other		(3,291)
Balance, end of period	192,471	173,343	147,178
Retail
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	166,810	139,320	122,025
Provision for credit losses	132,760	137,942	98,826
Charge-offs	(160,972)	(148,566)	(123,911)
Recoveries	47,656	41,405	42,380
Other		(3,291)
Balance, end of period	186,254	166,810	139,320
Wholesale
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	6,533	7,858	5,339
Provision for credit losses	(316)	(1,325)	2,519
Charge-offs	0	0	0
Recoveries	0	0	0
Other		0
Balance, end of period	$ 6,217	$ 6,533	$ 7,858