Stockholders' Deficit - Share-based Compensation Omnibus Incentive Plan (Details) - 2014 Omnibus Incentive Plan - shares	12 Months Ended
Dec. 31, 2018	May 22, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of shares of common stock authorized (in shares)		4,250,000
Additional shares added by amended plan (in shares)	2,199,114

Number of shares authorized for issuance under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant