Defined Benefit Plans (Korea Defined Benefit Plan) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2017
Defined Benefit Plan [Abstract]
Service cost	$ 134	$ 221
Interest cost	20	34
Net cost	$ 154	$ 255

Supplemental Unemployment Benefits, Net Periodic Benefit Cost

No definition available.

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Namespace Prefix:	mxwl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration