Investments	6 Months Ended
Jun. 30, 2019
Investments
Investments	10. Investments As of June 30, 2019, our investments consisted of U.S. Treasury securities, maturing at various dates through December 2019, and certificates of deposit with various financial institutions maturing in March 2020. U.S. Treasury securities are classified as short- or long-term investments on our consolidated balance sheets based on maturity and certificates of deposit are classified as short-term investments on our consolidated balance sheets. U.S Treasury securities are classified as available-for-sale and are recorded at fair value. Certificates of deposits are classified as held-to-maturity and are recorded at amortized cost, which approximates fair value. Total amortized cost and fair value were each $1.5 million as of June 30, 2019. Based on review of these securities, we believe that the cost basis of these available-for-sale securities is recoverable and that there were no other-than-temporary impairments on these securities as of June 30, 2019.

10. Investments

As of June 30, 2019, our investments consisted of U.S. Treasury securities, maturing at various dates through December 2019, and certificates of deposit with various financial institutions maturing in March 2020. U.S. Treasury securities are classified as short- or long-term investments on our consolidated balance sheets based on maturity and certificates of deposit are classified as short-term investments on our consolidated balance sheets. U.S Treasury securities are classified as available-for-sale and are recorded at fair value. Certificates of deposits are classified as held-to-maturity and are recorded at amortized cost, which approximates fair value.

Total amortized cost and fair value were each $1.5 million as of June 30, 2019. Based on review of these securities, we believe that the cost basis of these available-for-sale securities is recoverable and that there were no other-than-temporary impairments on these securities as of June 30, 2019.