GEOGRAPHIC INFORMATION - Schedule of Revenues Attributable to Product Groups, Services and Royalties (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Product revenue									$ 286,217	$ 355,579	$ 348,318
Service revenue									148,548	155,674	147,199
Royalty revenue									41,193	41,842	57,648
Total revenue	$ 120,029	$ 128,048	$ 117,025	$ 110,856	$ 147,798	$ 142,063	$ 135,106	$ 128,128	475,958	553,095	553,165
Tape automation systems
Segment Reporting, Revenue Reconciling Item [Line Items]
Product revenue									97,454	152,205	174,438
Disk backup systems
Segment Reporting, Revenue Reconciling Item [Line Items]
Product revenue									39,722	54,845	50,217
Devices and media
Segment Reporting, Revenue Reconciling Item [Line Items]
Product revenue									45,767	62,642	70,680
Scale-out storage solutions
Segment Reporting, Revenue Reconciling Item [Line Items]
Product revenue									$ 103,274	$ 85,887	$ 52,983