Income Taxes (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Income Tax Disclosure [Line Items]
Deferred tax asset, operating loss carryforwards	$ 1.8
Federal [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	57.6
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Valuation allowance, operating loss carryforwards	$ 0.3
Minimum [Member] | State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards, remaining life	1 year
Maximum [Member] | State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards, remaining life	20 years