Investments	9 Months Ended
Sep. 30, 2017
Investments
Investments	7. Investments As of September 30, 2017, our investments consisted of U.S. Treasury securities, maturing at various dates through January 2019, and certificates of deposit with various financial institutions maturing in November 2017. 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. As of September 30, 2017, all five of our U.S. Treasury securities were in an unrealized loss position, none of which had been in an unrealized loss position for 12 months or greater. Total amortized cost and fair value were each $24.9 million as of September 30, 2017. 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 September 30, 2017.

7. Investments

As of September 30, 2017, our investments consisted of U.S. Treasury securities, maturing at various dates through January 2019, and certificates of deposit with various financial institutions maturing in November 2017. 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.

As of September 30, 2017, all five of our U.S. Treasury securities were in an unrealized loss position, none of which had been in an unrealized loss position for 12 months or greater. Total amortized cost and fair value were each $24.9 million as of September 30, 2017. 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 September 30, 2017.