Stock-based Awards (Details - Options) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Additional disclosure
Stock-based compensation expense	$ 15,556	$ 8,972	$ 24,191	$ 18,069
Options
Number of Options
Outstanding at the beginning of period (in shares)			14,114,651
Granted (in shares)			2,022,047
Exercised (in shares)			(355,147)
Canceled/forfeited (in shares)			(2,701,845)
Outstanding at the end of the period (in shares)	13,079,706		13,079,706		14,114,651
Weighted-Average Exercise Price
Outstanding at the beginning of period (in dollars per share)			$ 12.32
Granted (in dollars per share)			7.06
Exercised (in dollars per share)			7.98
Canceled/forfeited (in dollars per share)			12.96
Outstanding at the end of the period (in dollars per share)	$ 11.50		$ 11.50		$ 12.32
Additional disclosure
Weighted average remaining contractual life (in years)			6 years 9 months 18 days		7 years
Remaining stock-based compensation expense for unvested awards	$ 17,600		$ 17,600
Weighted average period over which remaining stock based compensation expense for unvested awards is expected to be recognized			2 years 6 months
Stock-based compensation expense	$ 6,900	$ 3,800	$ 10,000	$ 8,400