Stock-based Compensation (Narrative) (Details) $ / shares in Units, $ in Millions		12 Months Ended
May 09, 2019	Dec. 31, 2019 USD ($) $ / shares shares
Reverse stock split ratio	0.0714	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		$ 3.25
Unrecognized compensation cost related to unvested options \| $		$ 7.4
Weighted-average remaining period for recognition of compensation costs related to unvested options		2 years
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 cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Number of shares issued under share-based payment arrangement.

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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 award under share-based payment arrangement.

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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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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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