Acquired Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 408	$ 408	$ 483
2017	356
2018	356
2019	356
2020	356
2021	$ 356
Customer Lists [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	7 years
Customer Lists [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	10 years
Patents [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	8 years
Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	5 years
Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	3 years
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	15 years