Note 3 - Investments	12 Months Ended
Note 3 - Investments	Dec. 31, 2016
Notes to Financial Statements
Cash and Cash Equivalents Disclosure [Text Block]	3. Investments All of the Company’s investments are classified as available-for-sale and are carried at fair value with unrealized gains and losses recorded as a component of accumulated other comprehensive income, net of related income taxes. The Company held bank certificates of deposits of $20.5 million and $25.8 million at December 31, 2016 and 2015, respectively. The Company also held corporate debt securities of $2.0 million at December 31, 2015. There were no unrealized gains or losses on the Company’s available-for-sale securities at December 31, 2016 or 2015.

The entire disclosure for cash and cash equivalent footnotes, which may include the types of deposits and money market instruments, applicable carrying amounts, restricted amounts and compensating balance arrangements. Cash and equivalents include: (1) currency on hand (2) demand deposits with banks or financial institutions (3) other kinds of accounts that have the general characteristics of demand deposits (4) short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments maturing within three months from the date of acquisition qualify.