Assets Held for Sale - Summary of Assets Held for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Discontinued Operations And Disposal Groups [Abstract]
Property and equipment, net	$ 409	$ 409
Assets held for sale	$ 409	$ 409

Amount classified as assets attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer.

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Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant