Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 3,458	$ 3,458
Trade names
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 3,410	$ 3,410
Amortization period of intangible assets	15 years