Investments	3 Months Ended
Mar. 31, 2018
Investments, All Other Investments [Abstract]
Investments	4. Investments Investments in Privately-Held Companies We adopted ASU 2016-01 in the three months ended March 31, 2018. See Note 1. As of March 31, 2018 and December 31, 2017, we held non-marketable equity investments of approximately $36.1 million in privately-held companies. Such equity investments do not have readily determinable fair values. To date, we have not recorded any adjustments to the carrying amounts of our equity investments resulting from impairment or observable price changes in orderly transactions for identical or similar investments of the same issuer.

Investments

3 Months Ended

Mar. 31, 2018

Investments, All Other Investments [Abstract]

4. Investments

Investments in Privately-Held Companies

We adopted ASU 2016-01 in the three months ended March 31, 2018. See Note 1. As of March 31, 2018 and December 31, 2017, we held non-marketable equity investments of approximately $36.1 million in privately-held companies. Such equity investments do not have readily determinable fair values. To date, we have not recorded any adjustments to the carrying amounts of our equity investments resulting from impairment or observable price changes in orderly transactions for identical or similar investments of the same issuer.