Equity Incentive Plans (Narrative) (Details) $ / shares in Units, $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($) $ / shares shares
Reverse stock split ratio	0.0714
Vesting percentage	100.00%
Assumed 2006 and 2016 Plan [Member]
Reverse stock split ratio	0.0714
Additional awards \| shares	0
Minimum [Member] \| Assumed 2006 and 2016 Plan [Member]
Expiration period of share-based payment award	2 years
Maximum [Member] \| Assumed 2006 and 2016 Plan [Member]
Expiration period of share-based payment award	4 years
Stock Option [Member]
Common stock closing price \| $ / shares	$ 4.01
Unrecognized compensation cost related to unvested options \| $	$ 11.5
Weighted-average remaining period for recognition of compensation costs related to unvested options	2 years 3 months 18 days
Equity Incentive Plan 2016 [Member]
Expiration period of share-based payment award	10 years
Vesting period of share-based compensation award	4 years

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Unrecognized cost of unvested options awarded to employees as compensation.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share instruments newly issued under a share-based compensation plan.

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Price of a single share of a number of saleable stocks of a company.

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Percentage of vesting of share-based compensation awards.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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