Short-term Investment Securities	3 Months Ended
Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Short-term Investment Securities	Short-term Investment SecuritiesThe 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 March 31, 2020 and December 31, 2019, the Company had $106.2 million and $105.3 million in short-term available-for-sale investment securities, respectively. During the three months ended March 31, 2020, these investments earned interest income at a weighted-average fixed rate of approximately 1.9%. For the three months ended March 31, 2020, an unrealized gain of $321 thousand, net of deferred taxes of $94 thousand, was recorded within accumulated other comprehensive income ("AOCI") related to these investment securities. For the three months ended March 31, 2019, an unrealized gain of $130 thousand, net of deferred taxes of $39 thousand, was recorded within AOCI related to these investment securities. The Company had no realized gains or losses related to these securities for the three months ended March 31, 2020 and March 31, 2019, as the Company did not sell any of these securities during these periods. As of March 31, 2020 and December 31, 2019, $425 thousand and $104 thousand, net of tax, respectively, remained in AOCI, related to these instruments.

Short-term Investment Securities

3 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Short-term Investment SecuritiesThe 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 March 31, 2020 and December 31, 2019, the Company had $106.2 million and $105.3 million in short-term available-for-sale investment securities, respectively. During the three months ended March 31, 2020, these investments earned interest income at a weighted-average fixed rate of approximately 1.9%. For the three months ended March 31, 2020, an unrealized gain of $321 thousand, net of deferred taxes of $94 thousand, was recorded within accumulated other comprehensive income ("AOCI") related to these investment securities. For the three months ended March 31, 2019, an unrealized gain of $130 thousand, net of deferred taxes of $39 thousand, was recorded within AOCI related to these investment securities. The Company had no realized gains or losses related to these securities for the three months ended March 31, 2020 and March 31, 2019, as the Company did not sell any of these securities during these periods. As of March 31, 2020 and December 31, 2019, $425 thousand and $104 thousand, net of tax, respectively, remained in AOCI, related to these instruments.