Investments	6 Months Ended
Jun. 30, 2019
Investments Debt And Equity Securities [Abstract]
Investments	8. Investments As a result of the restructuring of the eNeura debt security discussed in Note 7, the eNeura debt security was reclassified from an available for sale debt security to a held to maturity debt security at its fair value on the date of the restructuring. The unrealized gain included in accumulated other comprehensive income at the restructuring date continues to be included in accumulated other comprehensive income and is now being amortized to interest income over the remaining life of the Restructured Debt Security. The Restructured Debt Security will be evaluated for impairment based on management’s estimate of future cash collections discounted using the debt security’s original effective interest rate of 8%. Management’s estimate of future cash flows involves significant judgment regarding the timing, expected events, and amount of future cash collections. Decreases in management’s estimate of future cash collections could result in an other than temporary impairment. As of June 30, 2019, the Company’s amortized cost basis in the Restructured Note was $15.1 million, which also represents its carrying value, compared to an estimated fair value of $16.0 million and an unpaid principal balance of $15.0 million. During the three and six months ended June 30, 2019, the Company recognized $0.2 and $0.3 million in interest income related to the eNeura debt security. The Company did not recognize any interest income during the three and six months ended June 30, 2018.

Investments

6 Months Ended

Jun. 30, 2019

Investments Debt And Equity Securities [Abstract]

8. Investments

As a result of the restructuring of the eNeura debt security discussed in Note 7, the eNeura debt security was reclassified from an available for sale debt security to a held to maturity debt security at its fair value on the date of the restructuring. The unrealized gain included in accumulated other comprehensive income at the restructuring date continues to be included in accumulated other comprehensive income and is now being amortized to interest income over the remaining life of the Restructured Debt Security. The Restructured Debt Security will be evaluated for impairment based on management’s estimate of future cash collections discounted using the debt security’s original effective interest rate of 8%. Management’s estimate of future cash flows involves significant judgment regarding the timing, expected events, and amount of future cash collections. Decreases in management’s estimate of future cash collections could result in an other than temporary impairment. As of June 30, 2019, the Company’s amortized cost basis in the Restructured Note was $15.1 million, which also represents its carrying value, compared to an estimated fair value of $16.0 million and an unpaid principal balance of $15.0 million. During the three and six months ended June 30, 2019, the Company recognized $0.2 and $0.3 million in interest income related to the eNeura debt security. The Company did not recognize any interest income during the three and six months ended June 30, 2018.