Equity Award Plans - Summary of Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Number of Shares
Options granted	0	0
2006 and 2013 Plan [Member] | Stock Options [Member]
Number of Shares
Balance at beginning of period			436,000
Options granted			128,000
Options forfeited and cancelled			(14,000)
Balance at end of period	550,000		550,000	436,000
Options exercisable	356,000		356,000
Options vested	356,000		356,000
Options vested and expected to vest	527,000		527,000
Weighted?Average Exercise?Price Per?Share
Balance at beginning of period			$ 29.01
Options granted			4.00
Options forfeited and cancelled			62.96
Balance at end of period	$ 22.33		22.33	$ 29.01
Options exercisable	31.09		31.09
Options vested	31.09		31.09
Options vested and expected to vest	$ 23.04		$ 23.04
Weighted Average Remaining Contractual Term?(in?Years)
Options outstanding			6 years 11 months 12 days	6 years 9 months 14 days
Options granted			9 years 7 months 13 days
Options exercisable			5 years 9 months 18 days
Options vested			5 years 9 months 18 days
Options vested and expected to vest			6 years 10 months 6 days
Aggregate Intrinsic?Value
Options outstanding			$ 0
Options outstanding	$ 0		$ 0	$ 0