Quantum Corporation Annual report pursuant to Section 13 and 15(d)

GEOGRAPHIC INFORMATION - Schedule of Revenue and Long-Lived Assets by Region (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Long- Lived Assets	$ 14,653us-gaap_PropertyPlantAndEquipmentNet				$ 17,574us-gaap_PropertyPlantAndEquipmentNet				$ 14,653us-gaap_PropertyPlantAndEquipmentNet	$ 17,574us-gaap_PropertyPlantAndEquipmentNet	$ 21,456us-gaap_PropertyPlantAndEquipmentNet
Revenue	147,798us-gaap_Revenues	142,063us-gaap_Revenues	135,106us-gaap_Revenues	128,128us-gaap_Revenues	127,968us-gaap_Revenues	145,869us-gaap_Revenues	131,479us-gaap_Revenues	147,849us-gaap_Revenues	553,095us-gaap_Revenues	553,165us-gaap_Revenues	587,439us-gaap_Revenues
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long- Lived Assets	14,063				16,759				14,063	16,759	20,182
Revenue									340,811	359,259	378,514
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Long- Lived Assets	421				524				421	524	756
Revenue									152,186	143,508	151,676
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Long- Lived Assets	169				291				169	291	518
Revenue									$ 60,098	$ 50,398	$ 57,249