Other Intangible Assets (Additional Disclosures) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Amortization of other intangible assets	$ 2,700,000	$ 2,800,000	$ 3,000,000
Amortization of deferred financing costs	472,000	424,000	346,000
Impairment loss	$ 0	$ 0	$ 0
Minimum
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Amortization period	2 years
Maximum
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Amortization period	20 years