Quarterly report pursuant to Section 13 or 15(d)

REVISION OF PRIOR PERIOD FINANCIAL STATEMENTS (Details)

v2.4.1.9
REVISION OF PRIOR PERIOD FINANCIAL STATEMENTS (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 9 Months Ended
Dec. 31, 2013
Dec. 31, 2013
Mar. 31, 2013
Cumulative overstatement of revenue and accounts receivable      
Error Corrections And Prior Period Adjustments Revisions [Line Items]      
Cumulative error     $ 0.7qtm_QuantifyingMisstatementInPriorYearFinancialStatementsCumulativeAmount
/ us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis
= qtm_CumulativeOverstatementOfRevenueAndAccountsReceivableMember
Overstatement (understatement) of revenue      
Error Corrections And Prior Period Adjustments Revisions [Line Items]      
Amount of error 0.1qtm_QuantifyingMisstatementInPriorYearFinancialStatementsAmount
/ us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis
= qtm_OverstatementUnderstatementOfRevenueMember 		0.1qtm_QuantifyingMisstatementInPriorYearFinancialStatementsAmount
/ us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis
= qtm_OverstatementUnderstatementOfRevenueMember 		 
Cumulative overstatement of rent expense and total other accrued liabilities and other long-term liabilities      
Error Corrections And Prior Period Adjustments Revisions [Line Items]      
Cumulative error     2.1qtm_QuantifyingMisstatementInPriorYearFinancialStatementsCumulativeAmount
/ us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis
= qtm_CumulativeOverstatementOfRentExpenseAndTotalOtherAccruedLiabilitiesAndOtherLongTermLiabilitiesMember
Overstatement of general and administrative expense      
Error Corrections And Prior Period Adjustments Revisions [Line Items]      
Amount of error $ 0.1qtm_QuantifyingMisstatementInPriorYearFinancialStatementsAmount
/ us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis
= qtm_OverstatementOfGeneralAndAdministrativeExpenseMember 		$ 0.1qtm_QuantifyingMisstatementInPriorYearFinancialStatementsAmount
/ us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis
= qtm_OverstatementOfGeneralAndAdministrativeExpenseMember