Note 4 - Investments

9 Months Ended

Sep. 30, 2019

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 totaling

$69.8

million and

$70.0

million as of

September 30, 2019

and

December 31, 2018,

respectively. Unrealized gains and losses as well as the associated tax impact on the Company’s available-for-sale securities were immaterial as of

September 30, 2019

and

December 31, 2018.

All of the Company’s available-for-sale securities are estimated to mature in

one

year or less.