Income Taxes (Additional Disclosures) (Details)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2015 filing_group	Dec. 31, 2014 filing_group	Dec. 31, 2016 USD ($)
Income Tax Disclosure [Abstract]
Provisional expense for the effects of the 2017 Tax Act	$ 7,300,000
Provisional expense for remeasurement of net deferred tax assets for the effects of the 2017 Tax Act	5,500,000
Provisional expense for unrepatriated earnings from foreign subsidiaries for the effects of the 2017 Tax Act	200,000
Provisional expense for limitations on the deductibility of executive compensation for the effects of the 2017 Tax Act	1,600,000
Unrecognized tax benefits	0
Net operating loss carryforwards	103,800,000
Number of U.S. tax return filing groups | filing_group		1	2
Valuation allowance	1,187,000			$ 1,053,000
Unremitted earnings outside the US	$ 1,500,000