Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 3,458	$ 3,458
Less accumulated amortization	356	237
Intangible assets subject to amortization, net	3,102	3,221
Trade names
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	3,410	3,410
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 48	$ 48