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

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

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

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-Publisher FASB
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- Definition

In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

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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.

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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.

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- Definition

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

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- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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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.

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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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- Definition

This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (basic).

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- Details

Name:	dei_LegalEntityAxis=kem_KECMember
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- Details

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Acquisitions (Details) shares in Thousands, $ in Thousands, ¥ in Billions			3 Months Ended		6 Months Ended
	Apr. 19, 2017 USD ($) Rate	Apr. 19, 2017 JPY (¥) Rate	Sep. 30, 2018 USD ($) manufacturing_site shares	Sep. 30, 2017 USD ($) Rate shares	Sep. 30, 2018 USD ($) manufacturing_site shares	Sep. 30, 2017 USD ($) Rate shares	Dec. 31, 2017 USD ($) Rate	Dec. 31, 2017 JPY (¥) Rate	Apr. 14, 2017 USD ($)	Apr. 14, 2017 JPY (¥)	Mar. 31, 2017 Rate
Business Acquisition [Line Items]
Foreign Currency Exchange Rate, Translation \| Rate	10900.70%	10900.70%		11250.20%		11250.20%	11257.40%	11257.40%			11182.30%
Pro forma common shares - basic \| shares			57,799	49,819	57,570	48,607
Pro forma common shares - diluted \| shares			59,197	58,409	59,119	58,136
Equity income (loss) from equity method investments \| $			$ 64	$ 224	$ (5)	$ 75,641
Acquisition (gain) loss \| $			$ 0	$ (1,285)	$ 0	$ (136,873)
Business Acquisition Cost of Acquired Entity Working Capital Adjustment							$ 0	¥ 0.3
KEC [Member] \| TOKIN [Member]
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage	100.00%	100.00%
Business Acquisition, Percentage of Voting Interests Acquired	66.00%	66.00%
Payments to Acquire Businesses, Gross	$ 148,600	¥ 16.2
TOKIN [Member]
Business Acquisition [Line Items]
Number of Manufacturing Sites \| manufacturing_site			6		6
Disposal Group, Including Discontinued Operation, Consideration							$ 10,100	¥ 1.1	$ 431,000	¥ 48.2
Stock Purchase Agreement [Member] \| NEC TOKIN Corporation [Member] \| KEMET Electronics Corporation [Member]
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage			34.00%		34.00%
Excess cash [Member] \| KEC [Member] \| TOKIN [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	93,600	10.2
Cash Distribution [Member] \| KEC [Member] \| TOKIN [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 55,000	¥ 6.0