Debt - Revolving Line of Credit Narrative (Details)	12 Months Ended				0 Months Ended					0 Months Ended		12 Months Ended			12 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended				12 Months Ended					12 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Oct. 08, 2012 OEM USD ($)	Apr. 03, 2012 10.5% Senior Notes USD ($)	Mar. 27, 2012 10.5% Senior Notes USD ($)	May 05, 2010 10.5% Senior Notes USD ($)	Mar. 31, 2014 10.5% Senior Notes USD ($)	Mar. 31, 2013 10.5% Senior Notes USD ($)	Sep. 27, 2013 Revolving Line of Credit USD ($)	Sep. 24, 2013 Revolving Line of Credit USD ($)	Mar. 31, 2014 Revolving Line of Credit USD ($) letters_of_credit	Mar. 31, 2013 Revolving Line of Credit USD ($)	Sep. 30, 2010 Revolving Line of Credit USD ($)	Mar. 31, 2014 Revolving Line of Credit Greater than 33.3% and less than 66.6%	Mar. 31, 2014 Revolving Line of Credit Greater than or equal to 66.6%	Sep. 27, 2013 Revolving Line of Credit LIBOR	Mar. 31, 2014 Revolving Line of Credit LIBOR	Sep. 24, 2013 Revolving Line of Credit Base Rate	Mar. 31, 2014 Revolving Line of Credit Maximum Greater than 33.3% and less than 66.6%	Mar. 31, 2014 Revolving Line of Credit Maximum Greater than or equal to 66.6%	Mar. 31, 2014 Revolving Line of Credit KEMET Singapore	Sep. 30, 2010 Singapore facility USD ($)	Mar. 31, 2014 Singapore facility Minimum LIBOR	Mar. 31, 2014 Singapore facility Minimum Base Rate	Mar. 31, 2014 Singapore facility Maximum LIBOR	Mar. 31, 2014 Singapore facility Maximum Base Rate	Sep. 30, 2010 Singapore facility KEMET Singapore	Mar. 31, 2014 U.S. facility USD ($)	Mar. 31, 2014 U.S. facility Minimum LIBOR	Mar. 31, 2014 U.S. facility Minimum Base Rate	Mar. 31, 2014 U.S. facility Maximum LIBOR	Mar. 31, 2014 U.S. facility Maximum Base Rate	Sep. 30, 2010 U.S. facility KEC USD ($)	Mar. 31, 2014 Loan Security Agreement USD ($)	Mar. 31, 2014 Letter of Credit One USD ($)	Mar. 31, 2014 Letter of Credit One EUR (€)	Mar. 31, 2014 Letter of Credit Two USD ($)	Mar. 31, 2014 Letter of Credit Two EUR (€)
Debt Instrument [Line Items]
Maximum borrowing capacity														$ 50,000,000.0									$ 30,000,000.0
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)																	3.75%	1.00%	2.50%					2.75%	1.75%	3.25%	2.25%			2.50%	1.50%	3.00%	2.00%
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)							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)												15.00%
Cash Dominion Trigger Event, Availability under credit facility												7,500,000																	3,750,000
Percentage of assets pledged as collateral																						100.00%
Fixed charge coverage ratio												1.1
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)												15.00%
Required aggregate revolver commitments to maintain fixed charge coverage ratio												7,500,000																	3,750,000
Debt issuance cost, net of amortization								5,400,000	6,700,000			200,000	600,000
Aggregate principal amount					15,000,000	110,000,000	230,000,000			12,000,000	9,000,000
Effective interest rate (as a percent)								10.30%	10.40%	4.00%	5.75%
Debt instrument term										31 days
Borrowings outstanding												18,400,000																							16,900,000
Repayments of line of credit	2,551,000	0	0									2,600,000
Credit facility, remaining borrowing capacity																																			7,100,000
Amount of irrevocable standby letter of credit delivered				$ 16,000,000																																$ 1,500,000	€ 1,100,000	$ 900,000	€ 700,000
Number of Letters of Credit												2