Consolidated Valuation And Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts Receivable - Allowance For Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		$ 3,458	$ 4,960	$ 4,954
Provision charged to expense		266	(471)	245
Reserve adjustments		(276)	(394)	(136)
Write-offs, net of recoveries		(543)	(637)	(103)
Balance at end of period		2,905	3,458	4,960
Finance Receivables - Allowance For Credit Losses [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		127,364	110,693	107,667
Provision charged to expense		101,345	80,946	60,008
Write-offs, net of recoveries		(81,531)	(64,275)	(56,982)
Balance at end of period		147,178	127,364	110,693
Inventories - Allowance For Obsolescence [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	[1]	17,775	17,463	22,936
Provision charged to expense	[1]	19,564	19,044	5,254
Reserve adjustments	[1]	(1,028)	(399)	(1,281)
Write-offs, net of recoveries	[1]	(9,571)	(18,333)	(9,446)
Balance at end of period	[1]	26,740	17,775	17,463
Deferred Tax Assets - Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		25,462	21,818	16,314
Reserve adjustments		(4,803)	3,644	5,504
Balance at end of period		$ 20,659	$ 25,462	$ 21,818

[1] Inventory obsolescence reserves deducted from cost determined on first-in first-out (FIFO) basis, before deductions for last-in, first-out (LIFO) valuation reserves.