Note 8 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2012

Fair Value, by Balance Sheet Grouping [Table Text Block]

	Estimated Fair Market Value as of
	September 30, 2012		December 31, 2011
Cash, Cash Equivalents and Investments
Cash in Banks	$	51,153	$	43,305
Money Market Funds		27,094		51,066
Government Agencies/ Treasuries		107,279		79,827
Auction-Rate Securities backed by Student-Loan Notes		11,756		13,675
Total Cash, Cash Equivalents and Investments	$	197,282	$	187,873

Schedule of Other Current Assets [Table Text Block]

	September 30,		December 31,
Reported as:	2012		2011
Cash and Cash Equivalents	$	78,247	$	96,371
Short-term Investments		107,279		77,827
Long-term Investments		11,756		13,675
Total Cash, Cash Equivalents and Investments	$	197,282	$	187,873

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30,		December 31,
	2012		2011
Due in less than 1 year		33,998		45,133
Due in 1 - 5 years		73,281		32,694
Due in greater than 5 years		11,756		13,675
		119,035		91,502

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	Fair Value Measurements at September 30, 2012 Using
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Money Market Funds	$	27,094	$	27,094	$	-	$	-
US Treasuries and US Government Agency Bonds		107,279				107,279		-
Long-term available-for-sale auction-rate securities		11,756		-		-		11,756
	$	146,129	$	27,094	$	107,279	$	11,756

	Fair Value Measurements at December 31, 2011 Using
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Money Market Funds	$	51,066	$	51,066	$	-	$	-
US Treasuries and US Government Agency Bonds		79,827		-		79,827		-
Long-term available-for-sale auction-rate securities		13,675		-		-		13,675
	$	144,568	$	51,066	$	79,827	$	13,675

Unrealized Gain (Loss) on Investments [Table Text Block]

	As of September 30, 2012
	Adjusted Cost		Unrealized gains or losses			Total Fair Value		Fair Value of Investments in Unrealized Loss Position
Money Market Funds	$	27,094	$	-		$	27,094	$	-
US Treasuries and US Government Agency Bonds		107,241		37			107,279		22,080
Auction-rate securities backed by Student-Loan Notes		12,245		(489	)		11,756		11,756
	$	146,580	$	(452	)	$	146,129	$	33,836

	As of December 31, 2011
	Adjusted Cost		Unrealized Gains or Losses			Total Fair Value		Fair Value of Investments in Unrealized Loss Position
Money Market Funds	$	51,066	$	-		$	51,066	$	-
US Treasuries and US Government Agency Bonds		79,830		(3	)		79,827		25,281
Auction-rate securities backed by Student-Loan Notes		14,305		(630	)		13,675		13,675
	$	145,201	$	(633	)	$	144,568	$	38,956

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Auction-Rate Securities
Ending balances at December 31, 2011	$	13,675
Sales and Settlement at Par		(100	)
Total realized and unrealized gains (losses):
Included in other income (expense)		-
Included in other comprehensive income		90
Ending balances at March 31, 2012	$	13,665
Sales and Settlement at Par		(2,000	)
Total realized and unrealized gains (losses):
Included in other income (expense)		40
Included in other comprehensive income		9
Ending balances at June 30, 2012	$	11,714
Sales and Settlement at Par		-
Total realized and unrealized gains (losses):
Included in other income (expense)		-
Included in other comprehensive income		42
Ending balances at September 30, 2012	$	11,756