Note 4 - Investments

3 Months Ended

Mar. 31, 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

$71.2

million and

$70.0

million as of

March 31, 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

March 31, 2019

and

December 31, 2018.