Represents the working capital adjustment associated with the acquisition of the acquired entity.

No definition available.

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- Definition

Represents the number of manufacturing sites operated by the entity.

+ References

No definition available.

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- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(12))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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- Definition

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.

+ References

No definition available.

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- Definition

Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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- Definition

Fair value at acquisition-date of the equity interest in the acquiree held by the acquirer, immediately before the acquisition date for businesses combined in stages.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)(1)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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Balance Type:	credit
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- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

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Balance Type:	na
Period Type:	instant

- Definition

Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section S99
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6897108&loc=SL6897125-166521

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=kem_TOKINMember
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- Details

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- Details

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- Details

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Data Type:	na
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- Details

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Acquisitions - Narrative (Details) $ in Thousands, ¥ in Billions				12 Months Ended
	Apr. 19, 2017 USD ($)	Apr. 19, 2017 JPY (¥) Rate	Feb. 01, 2013 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) manufacturing_site Rate	Dec. 31, 2017 JPY (¥) manufacturing_site Rate	Sep. 30, 2017 Rate	Apr. 14, 2017 USD ($)	Apr. 14, 2017 JPY (¥)	Mar. 31, 2017 USD ($) Rate	Mar. 31, 2016	Mar. 12, 2012
Acquisitions
Exchange rate \| Rate		10900.70%			11257.40%	11257.40%	11250.20%			11182.30%
Working capital adjustment					$ 0	¥ 0.3
Assets				$ 1,218,269						$ 734,325
TOKIN
Acquisitions
Transaction expenses					$ 900
Revenue				358,200
Assets				$ 36,100
TOKIN
Acquisitions
Number of manufacturing sites \| manufacturing_site					6	6
Purchase price		¥ 10.2			$ 10,100	¥ 1.1		$ 431,000	¥ 48.2
KEC \| TOKIN
Acquisitions
Ownership percentage		100.00%
Interest acquired		66.00%
Purchase price paid	$ 148,600	¥ 16.2
KEC \| Cash Distribution \| TOKIN
Acquisitions
Purchase price paid	55,000	6.0
KEC \| Excess cash \| TOKIN
Acquisitions
Purchase price paid	93,600	¥ 10.2
NEC TOKIN Corporation \| KEMET Electronics Corporation
Acquisitions
Transaction expenses			$ 4,500
NEC TOKIN Corporation \| KEMET Electronics Corporation \| Stock Purchase Agreement
Acquisitions
Ownership percentage				34.00%	34.00%	34.00%				34.00%	34.00%	34.00%
Purchase price paid			$ 50,000
Equity interest in acquiree	$ 204,112