Stockholders' Equity - Share-based Compensation Omnibus Incentive Plan (Details) - 2014 Omnibus Incentive Plan - shares	6 Months Ended
Jun. 30, 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

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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