Debt - Revolving Line of Credit Narrative (Details)	12 Months Ended				0 Months Ended				12 Months Ended							12 Months Ended		12 Months Ended											12 Months Ended		0 Months Ended					12 Months Ended			12 Months Ended
	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Oct. 08, 2012 OEM USD ($)	Sep. 27, 2013 Foreign Line of Credit [Member]	Mar. 31, 2015 Foreign Line of Credit [Member] USD ($)	Mar. 31, 2014 Foreign Line of Credit [Member] USD ($)	Sep. 30, 2010 Foreign Line of Credit [Member] USD ($)	Mar. 31, 2015 Foreign Line of Credit [Member] Base Rate	Mar. 31, 2014 Foreign Line of Credit [Member] Base Rate	Mar. 31, 2015 Foreign Line of Credit [Member] Minimum LIBOR	Mar. 31, 2015 Foreign Line of Credit [Member] Minimum Base Rate	Mar. 31, 2015 Foreign Line of Credit [Member] Maximum LIBOR	Mar. 31, 2015 Foreign Line of Credit [Member] Maximum Base Rate	Sep. 30, 2010 Foreign Line of Credit [Member] KEMET Singapore	Mar. 31, 2015 Domestic Line of Credit [Member] USD ($)	Mar. 31, 2014 Domestic Line of Credit [Member] USD ($)	Mar. 31, 2015 Domestic Line of Credit [Member] Base Rate	Mar. 31, 2014 Domestic Line of Credit [Member] Base Rate	Mar. 31, 2015 Domestic Line of Credit [Member] Minimum LIBOR	Mar. 31, 2015 Domestic Line of Credit [Member] Minimum Base Rate	Mar. 31, 2015 Domestic Line of Credit [Member] Maximum LIBOR	Mar. 31, 2015 Domestic Line of Credit [Member] Maximum Base Rate	Sep. 30, 2010 Domestic Line of Credit [Member] KEC USD ($)	Mar. 31, 2014 Letter of Credit Two USD ($)	Mar. 31, 2014 Letter of Credit Two EUR (€)	Mar. 31, 2014 Letter of Credit Three [Member] USD ($)	Mar. 31, 2014 Letter of Credit Three [Member] EUR (€)	Mar. 31, 2015 Letter of Credit One USD ($)	Mar. 31, 2014 Letter of Credit One USD ($)	Apr. 03, 2012 10.5% Senior Notes USD ($)	Mar. 27, 2012 10.5% Senior Notes USD ($)	May 05, 2010 10.5% Senior Notes USD ($)	Mar. 31, 2015 10.5% Senior Notes USD ($)	Mar. 31, 2014 10.5% Senior Notes USD ($)	Mar. 31, 2015 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2014 Revolving Credit Facility [Member] USD ($) letters_of_credit	Sep. 30, 2010 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2015 Revolving Credit Facility [Member] Greater than 33.3% and less than 66.6%	Mar. 31, 2015 Revolving Credit Facility [Member] Greater than or equal to 66.6%	Mar. 31, 2015 Revolving Credit Facility [Member] LIBOR	Mar. 31, 2015 Revolving Credit Facility [Member] Maximum Greater than 33.3% and less than 66.6%	Mar. 31, 2015 Revolving Credit Facility [Member] Maximum Greater than or equal to 66.6%	Mar. 31, 2015 Revolving Credit Facility [Member] KEMET Singapore
Debt Instrument [Line Items]
Maximum borrowing capacity								$ 30,000,000.0																												$ 75,000,000		$ 50,000,000.0
Line of Credit Facility, Current Borrowing Capacity																																						60,000,000
Borrowing base component one, percentage of borrower's accounts receivable that satisfy certain eligibility criteria															85.00%									85.00%
Borrowing base component two, fixed amount for determining second component for borrowing base																								6,000,000
Borrowing base component two, percentage of net book value of inventory of borrower that satisfies certain eligibility criteria																								40.00%
Borrowing base component three, percentage of net orderly liquidation percentage of the appraised value of inventory that satisfies certain eligibility criteria																								85.00%
Borrowing base component three, fixed amount for determining second component for borrowing base																								5,100,000
Borrowing base component three, percentage of net orderly liquidation percentage of the appraised value of equipment that satisfies certain eligibility criteria																								80.00%
Borrowing base component three, order liquidation reduction percentage																								0.05%
Spread on variable rate basis (as a percent)									2.75%	3.75%	2.25%	1.25%	2.75%	1.75%				1.50%	2.50%	2.00%	1.00%	2.50%	1.50%																		1.00%
Unused line fee (as a percent)																																							0.50%	0.375%
Average daily balance as percentage of total revolving commitment																																										50.00%	50.00%
Stated interest rate (as a percent)									3.13%	0.00%								4.75%	5.75%														10.50%	10.50%	10.50%
Cash Dominion Trigger Event, Number of days Considered																5 days																				5 days
Cash Dominion Trigger Event, Availability under credit facility (as a percent)																																				12.50%
Cash Dominion Trigger Event, Availability under credit facility																3,750,000																				7,500,000
Percentage of assets pledged as collateral																																												100.00%
Fixed charge coverage ratio																																				1.0
Consecutive period of non occurrence of any condition to maintain fixed charge coverage ratio																																				45 days
Required aggregate revolver commitments to maintain fixed charge coverage ratio (as a percent)																																				12.50%
Required aggregate revolver commitments to maintain fixed charge coverage ratio																3,750,000																				7,500,000
Debt issuance cost, net of amortization																																		4,100,000	5,400,000	300,000	200,000
Proceeds from Issuance of Debt																													33,400,000	18,400,000	15,000,000	110,000,000	230,000,000
Line of Credit Facility, Fair Value of Amount Outstanding						12,000,000	12,000,000									21,500,000	6,400,000
Effective interest rate (as a percent)																																		10.30%
Debt instrument term					90 days
Document Period End Date	Mar. 31, 2015
Repayments of line of credit	27,342,000	2,551,000	0																										27,300,000
Credit facility, remaining borrowing capacity																													13,400,000									15,000,000
Amount of irrevocable standby letter of credit delivered				$ 16,000,000																					$ 1,200,000	€ 1,100,000	$ 700,000	€ 700,000
Number of Letters of Credit																																					2