INVENTORIES (Schedule of Service Parts Inventories) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Mar. 31, 2014
Service parts inventories:
Finished goods	$ 17,663qtm_ServicePartsInventoryFinishedGoods	$ 17,926qtm_ServicePartsInventoryFinishedGoods
Component parts	6,698qtm_ServicePartsInventoryComponentParts	7,703qtm_ServicePartsInventoryComponentParts
Service parts inventories	$ 24,361qtm_ServicePartsInventories	$ 25,629qtm_ServicePartsInventories

Carrying amount as of the balance sheet date of component parts held by the company as service parts.

No definition available.

Name:	qtm_ServicePartsInventoryComponentParts
Namespace Prefix:	qtm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant