Revenue from Contracts with Customers - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)
Revenue from Contract with Customer [Abstract]
Capitalized contract costs, current	$ 0.9	$ 0.9
Amortization of contract costs	$ 0.3	$ 0.9

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as current.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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