Note 5. Short-Term Investments (Tables)

6 Months Ended

Jun. 30, 2012

Available-for-sale Securities [Table Text Block]

	June 30, 2012
				Unrealized
	Amortized Cost			Gains			Losses				Estimated Fair Value
Commercial paper		$	4,495		$	1		$	-			$	4,496
Municipal bonds			122,189			15			(30	)			122,174
Corporate bonds			8,146			4			(2	)			8,148
U.S. government and agency securities			17,009			-			(10	)			16,999
		$	151,839		$	20		$	(42	)		$	151,817