The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 110	$ 110	$ 331	$ 317
2018	442		442
2019	412		412
2020	406		406
2021	406		406
2022	$ 88		$ 88
Customer Lists [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			7 years
Customer Lists [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			10 years
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			18 years
Software [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			3 years
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			15 years
Non-compete Agreements [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			2 years
Non-compete Agreements [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization period			5 years