Income Taxes (Income Tax Benefit Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax provision (benefit) at statutory U.S. federal income tax rate	$ 3,455	$ (17,194)	$ 128
State income tax — net of federal income tax benefit	937	(1,746)	(227)
Impact of Tax Cuts and Job Act		(15,720)
Change in state law regarding NOL carryforwards	658
Nondeductible officer compensation	201
Change in deferred state tax rate			(1,043)
Research and development tax credits	(218)	(170)	(253)
Changes in unrecognized tax benefits	14	10	10
Changes in valuation allowance	116	1,152	821
Other	274	(93)	387
Income tax provision (benefit)	$ 5,437	$ (33,761)	$ (177)

Income tax expense (benefit) excluding discontinued operations.

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Income tax reconciliation change in deferred state tax rate

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Income tax reconciliation change in state law regarding non operating loss carryforwards.

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Income tax reconciliation, changes in unrecognized tax benefits

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Income tax reconciliation nondeductible expense officer compensation.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

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