Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Increase (decrease) in valuation allowance	$ 2.7	$ 3.2
Internal Revenue Service I R S [Member]
Net operating loss carryforwards	166.2	$ 15.4
Internal Revenue Service I R S [Member] \| Research [Member]
Tax credit carryforwards	$ 1.3
Internal Revenue Service I R S [Member] \| Minimum [Member]
Expiration year	Dec. 31, 2021
Internal Revenue Service I R S [Member] \| Minimum [Member] \| Research [Member]
Expiration year	Dec. 31, 2022
Internal Revenue Service I R S [Member] \| Maximum [Member]
Expiration year	Dec. 31, 2037
Internal Revenue Service I R S [Member] \| Maximum [Member] \| Research [Member]
Expiration year	Dec. 31, 2035
State And Local Jurisdiction [Member]
Net operating loss carryforwards	$ 172.0
State And Local Jurisdiction [Member] \| Research [Member]
Tax credit carryforwards	$ 2.2
State And Local Jurisdiction [Member] \| Minimum [Member]
Expiration year	Dec. 31, 2028
State And Local Jurisdiction [Member] \| Maximum [Member]
Expiration year	Dec. 31, 2039

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
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The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 20
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