Note 4 - Investments

9 Months Ended

Sep. 30, 2018

Notes to Financial Statements

Cash and Cash Equivalents Disclosure [Text Block]

4. Investments

All of the Company’s investments 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 investments, including U.S. treasury bills and bank certificates of deposit, totaling

$67.2

million and

$24.0

million as of

September 30, 2018

and

December 31, 2017,

respectively. Unrealized losses and associated tax impact on the Company’s available-for-sale securities were immaterial compared to

$0

as of

September 30, 2018

and

December 31, 2017,

respectively.