Revenue Voluntary Recall (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Provision for sales returns	$ 4.5	$ 11.3

Amount of estimated sales returns.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790

Name:	us-gaap_RevenueRecognitionSalesReturnsReserveForSalesReturns
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration