Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2011

Summary Of Significant Accounting Policies [Abstract]

Marketable Securities

	December  31, 2011		December  31, 2010
Available-for-sale:
Corporate bonds	$	153,380	$	50,231
U.S. Treasuries		—		89,887
	$	153,380	$	140,118

Changes In Warranty And Safety Recall Liability

	2011			2010			2009
Balance, beginning of period	$	54,134		$	68,044		$	64,543
Warranties issued during the period		44,092			36,785			51,336
Settlements made during the period		(55,386	)		(58,067	)		(74,022	)
Recalls and changes to pre-existing warranty liabilities		12,154			7,372			26,187
Balance, end of period	$	54,994		$	54,134		$	68,044