Merger Agreement with Tesla (Details) $ / shares in Units, $ in Thousands	Feb. 03, 2019 USD ($) $ / shares shares
Business Combination, Separately Recognized Transactions [Line Items]
Number of business days following Tesla filing date	4 days
Number of months from offer before termination	5 months
Maxwell Technologies, Inc.
Business Combination, Separately Recognized Transactions [Line Items]
Share price (in dollars per share)	$ 4.75
Number of Tesla shares at volume weighted average closing sale price \| shares	1
Number of trading days used to determine trading price	5 days
Tesla Trading Price (equal to or less than)	$ 245.90
Exchange ratio	0.0193
Termination fee \| $	$ 8,295

Business Acquisition, Number of Prevailing Trading Days used to Determine Share Price

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Business Combination, Acquirer Trading Price, Maximum

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Business Combination, Number of Months From Offer Before Termination

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Business Combination, Share Exchange Ratio

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Business Combination, Termination Fee to be Paid to Acquirer per Agreement if Acquisition is Unapproved

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Maximum Number of Days Following Reporting Date

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Number of Acquiring Company Shares Received Per Share Price

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Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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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.

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