Note 7 - Cash, Cash Equivalents and Investments (Details) (USD $)				6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended		6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2014 Temporary [Member]	Dec. 31, 2013 Temporary [Member]	Jun. 30, 2014 Other Than Temporary [Member]	Dec. 31, 2013 Other Than Temporary [Member]	Dec. 31, 2013 Auction Rate [Member]	Jun. 30, 2014 Auction Rate Securities Backed By Student-Loan Notes [Member]	Jun. 30, 2014 Government Backed Securities [Member]	Dec. 31, 2013 Government Backed Securities [Member]
Note 7 - Cash, Cash Equivalents and Investments (Details) [Line Items]
Auction Rate Securities, Noncurrent	$ 9,848,000	$ 9,843,000	$ 9,860,000							$ 9,800,000	$ 9,900,000
Other than Temporary Impairment Losses, Investments				372,000	360,000	30,000	30,000	390,000	402,000
Deferred Compensation Plan Assets	3,053,000		607,000
Deferred Compensation Liability, Current and Noncurrent	$ 3,100,000		$ 600,000