Note 9 - Cash, Cash Equivalents and Investments (Tables)

9 Months Ended

Sep. 30, 2014

Disclosure Text Block Supplement [Abstract]

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

	September 30,		December 31,
	2014		2013
Cash, cash equivalents and investments:
Cash	$	72,709	$	62,625
Money market funds		29,103		35,588
U.S. treasuries and government agency bonds		126,849		128,126
Auction-rate securities backed by student-loan notes		9,795		9,860
Total	$	238,456	$	236,199

Schedule of Other Current Assets [Table Text Block]

	September 30,		December 31,
	2014		2013
Reported as:
Cash and cash equivalents	$	101,812	$	101,213
Short-term investments		126,849		125,126
Long-term investments		9,795		9,860
Total	$	238,456	$	236,199

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30,		December 31,
	2014		2013
Due in less than 1 year	$	79,562	$	95,509
Due in 1 - 5 years		47,287		29,617
Due in greater than 5 years		9,795		9,860
Total	$	136,644	$	134,986

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

	As of September 30, 2014
	Adjusted Cost		Unrealized Gains		Unrealized Losses			Total Fair Value		Fair Value of Investments in Unrealized Loss Position
Money market funds	$	29,103	$	-	$	-		$	29,103	$	-
U.S. treasuries and government agency bonds		126,861		37		(49	)		126,849		37,455
Auction-rate securities backed by student-loan notes		10,220		-		(425	)		9,795		9,795
Total	$	166,184	$	37	$	(474	)	$	165,747	$	47,250

	As of December 31, 2013
	Adjusted Cost		Unrealized Gains		Unrealized Losses			Total Fair Value		Fair Value of Investments in Unrealized Loss Position
Money market funds	$	35,588	$	-	$	-		$	35,588	$	-
U.S. treasuries and government agency bonds		128,123		26		(23	)		128,126		42,880
Auction-rate securities backed by student-loan notes		10,220		-		(360	)		9,860		9,860
Total	$	173,931	$	26	$	(383	)	$	173,574	$	52,740