Revenue Recognition - Product Warranties (Details)	6 Months Ended
Jun. 30, 2018
Minimum
Product Warranties
Product warranty term	1 year
Maximum
Product Warranties
Product warranty term	3 years

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ProductWarrantyLiabilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration