Stock-based Awards (Details - Options) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Additional disclosure
Stock-based compensation expense	$ 7,191	$ 10,247	$ 31,382	$ 28,316
Options
Number of Options
Outstanding at the beginning of period (in shares)			14,114,651
Granted (in shares)			2,115,973
Exercised (in shares)			(363,609)
Canceled/forfeited (in shares)			(4,983,186)
Outstanding at the end of the period (in shares)	10,883,829		10,883,829		14,114,651
Weighted-Average Exercise Price
Outstanding at the beginning of period (in dollars per share)			$ 12.32
Granted (in dollars per share)			6.95
Exercised (in dollars per share)			7.84
Canceled/forfeited (in dollars per share)			12.72
Outstanding at the end of the period (in dollars per share)	$ 11.25		$ 11.25		$ 12.32
Additional disclosure
Weighted average remaining contractual life (in years)			5 years 7 months 6 days		7 years
Remaining stock-based compensation expense for unvested awards	$ 15,300		$ 15,300
Weighted average period over which remaining stock based compensation expense for unvested awards is expected to be recognized			2 years 3 months 18 days
Stock-based compensation expense	$ 1,900	$ 4,200	$ 11,900	$ 12,600