INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Federal statutory rate (as a percent)	35.00%
Increase (decrease) in valuation allowance	$ (28,300)	$ (8,900)	$ (8,000)
Increase in balances related to tax positions taken in prior period	411	$ 0	$ 388
Total unrecognized tax benefit including interest and penalties	34,100
Accrued interest and penalties	1,200
Federal net operating loss	351,100
Tax credit carryforwards	90,400
Federal net operating loss carryforwards attributable to excess tax deductions from stock option exercises	34,300
Acquired net operating losses included in carryforwards	11,100
Acquired credits included in carryforwards	$ 10,700