SHARE-BASED COMPENSATION - Options Rollforward (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
2010 Equity Incentive Plan
Option Activity
Outstanding, beginning of fiscal year, Options (in shares)	15,992,894	23,612,872	34,405,564
Granted (in shares)	0	15,000	0
Exercised, Options (in shares)	(10,006,774)	(3,600,900)	(6,572,383)
Forfeited, Options (in shares)	(3,616,484)	(4,034,078)	(4,220,309)
Outstanding, end of fiscal year, Options (in shares)	2,369,636	15,992,894	23,612,872
Options exercisable, end of fiscal year, Options (in shares)	2,359,527	15,959,173	23,373,101
Weighted Average Exercise Price Activity
Outstanding, beginning of fiscal year, Price (in dollars per share)	$ 7.81	$ 8.57	$ 8.29
Granted, Price (in dollars per share)	0.00	11.11	0.00
Exercised, Price (in dollars per share)	6.10	6.53	4.28
Forfeited, Price (in dollars per share)	12.23	13.17	12.93
Outstanding, end of fiscal year, Price (in dollars per share)	8.31	7.81	8.57
Options exercisable, end of fiscal year, Price (in dollars per share)	$ 8.30	$ 7.81	$ 8.58
Exercises in period, intrinsic value	$ 55.3	$ 16.3	$ 24.7
Cash received from option exercises	$ 61.1	$ 23.5	$ 28.1
2014 NEXTracker Equity Incentive Plan
Option Activity
Outstanding, beginning of fiscal year, Options (in shares)	0
Granted (in shares)	3,205,806
Exercised, Options (in shares)	(237,380)
Forfeited, Options (in shares)	(226,572)
Outstanding, end of fiscal year, Options (in shares)	2,741,854	0
Options exercisable, end of fiscal year, Options (in shares)	223,869
Weighted Average Exercise Price Activity
Outstanding, beginning of fiscal year, Price (in dollars per share)	$ 0.00
Granted, Price (in dollars per share)	3.28
Exercised, Price (in dollars per share)	0.99
Forfeited, Price (in dollars per share)	3.75
Outstanding, end of fiscal year, Price (in dollars per share)	3.44	$ 0.00
Options exercisable, end of fiscal year, Price (in dollars per share)	$ 4.95
Cash received from option exercises	$ 0.2