Equity Award Plans, Stock Options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Aggregate Intrinsic Value Abstract]
Options outstanding	$ 0
Options vested and expected to vest	$ 0
2006 and 2013 Plan [Member] | Stock Options [Member]
Number of Shares [Roll Forward]
Balance at beginning of period (in shares)	436
Options granted (in shares)	128
Options forfeited and cancelled (in shares)	(11)
Balance at end of period (in shares)	553	436
Options exercisable (in shares)	350
Options vested (in shares)	350
Options vested and expected to vest (in shares)	525
Weighted Average Exercise Price Per Share [Roll Forward]
Balance at beginning of period (in dollars per share)	$ 29.01
Options granted (in dollars per share)	4.00
Options forfeited and cancelled (in dollars per share)	67.56
Balance at end of period (in dollars per share)	22.48	$ 29.01
Options exercisable (in dollars per share)	31.75
Options vested (in dollars per share)	31.75
Options vested and expected to vest (in dollars per share)	$ 23.33
Weighted Average Remaining Contractual Term [Abstract]
Options outstanding	6 years 7 months 6 days	6 years 9 months 14 days
Options granted	9 years 10 months 13 days
Options exercisable	5 years 11 months 19 days
Options vested	5 years 11 months 19 days
Options vested and expected to vest	7 years 22 days
Aggregate Intrinsic Value Abstract]
Options outstanding	$ 0
Options outstanding		$ 0