Short-term Investment Securities

6 Months Ended

Jun. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]

Short-term Investment Securities

The Company's short-term investment securities are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of 12 months or less. These securities are stated at fair value within current assets on the Company's condensed balance sheets. Realized gains and losses on sales of investments, if any, are reflected in non-operating income (expense) in the condensed statements of operations.

As of June 30, 2019 and December 31, 2018, the Company had $104.2 million and $102.8 million in short-term available-for-sale investment securities, respectively. During the six months ended June 30, 2019, these investments earned interest income at a weighted-average fixed rate of approximately 2.4%. For the three and six months ended June 30, 2019, an unrealized gain of $98 thousand and $228 thousand, net of deferred taxes of $29 thousand and $67 thousand, respectively, was recorded within accumulated other comprehensive income ("AOCI") related to these investment securities. For the three and six months ended June 30, 2018, an unrealized gain of $101 thousand and $78 thousand, net of deferred taxes of $33 thousand and $26 thousand, respectively, was recorded within AOCI related to these investment securities. The Company has not recognized any realized gains or losses related to these securities as the Company has not sold any of these securities. As of June 30, 2019 and December 31, 2018, $154 thousand and $74 thousand, net of tax, respectively, remained in AOCI, related to these instruments.