Income Taxes (Summary of Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Balance at January 1	$ 850,000	$ 0
Additions for tax positions of prior years	8,000	850,000
Reduction for tax positions of prior years	(294,000)
Balance at December 31	$ 564,000	$ 850,000