Note 8 - Fair Value Measurements (Detail) (USD $)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Mar. 31, 2012	Dec. 31, 2009
Available-for-sale Securities	$ 103,000,000	$ 103,000,000
Deposits, Money Market Deposits	30,100,000	30,100,000		51,100,000
Trading Securities, Change in Unrealized Holding Gain (Loss)	40,000	22,000		17,000
Auction Rate Securities, Noncurrent	11,714,000	11,714,000		13,675,000	13,665,000
Cash Equivalents, at Carrying Value				2,000,000
Other than Temporary Impairment Losses, Investments	(9,000)	(99,000)	(140,000)	700,000
Other Investments						6,300,000
Cash Flow Model Input Expected Return	1.80%	1.80%		1.80%
Government Backed Securities [Member]
Auction Rate Securities, Noncurrent	11,700,000	11,700,000
Auction Rate Securities Backed By Student-Loan Notes [Member]
Other than Temporary Impairment Losses, Investments		560,000
Temporary [Member]
Other than Temporary Impairment Losses, Investments		530,000		600,000
Other Than Temporary [Member]
Other than Temporary Impairment Losses, Investments		30,000		100,000
Face Value [Member]
Auction Rate Securities, Noncurrent	12,300,000	12,300,000
Minimum [Member]
Cash Flow Model Input Discount Rate	2.60%	2.60%		3.10%
Maximum [Member]
Cash Flow Model Input Discount Rate	7.40%	7.40%		7.90%
Government Backed Securities [Member]
Available-for-sale Securities, Current				77,800,000
Auction Rate Securities [Member]
Auction Rate Securities, Noncurrent				$ 14,400,000