SHARE-BASED COMPENSATION - Options Rollforward (Details) - $ / shares	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Option Activity
Outstanding, beginning of fiscal year, Options (in shares)	142,327	2,369,636	15,992,894
Granted (in shares)	0	0	0
Exercised, Options (shares)	(125,949)	(1,573,356)	(10,006,774)
Forfeited, Options (in shares)	(9,500)	(653,953)	(3,616,484)
Outstanding, end of fiscal year, Options (in shares)	6,878	142,327	2,369,636
Options exercisable, end of fiscal year, Options (in shares)	5,751	138,950	2,359,527
Weighted Average Exercise Price Activity
Outstanding, beginning of fiscal year, Price (in dollars per share)	$ 8.97	$ 8.31	$ 7.81
Granted, Price (in dollars per share)	0.00	0.00	0.00
Exercised, Price (in dollars per share)	8.63	6.89	6.10
Forfeited, Price (in dollars per share)	11.55	12.39	12.23
Outstanding, end of fiscal year, Price (in dollars per share)	9.78	8.97	8.31
Options exercisable, end of fiscal year, Price (in dollars per share)	$ 9.52	$ 8.93	$ 8.30
2014 NEXTracker Equity Incentive Plan
Option Activity
Outstanding, beginning of fiscal year, Options (in shares)	1,636,016	2,741,854	0
Granted (in shares)	288,386	0	3,205,806
Exercised, Options (shares)	(510,322)	(709,845)	(237,380)
Forfeited, Options (in shares)	(352,820)	(395,993)	(226,572)
Outstanding, end of fiscal year, Options (in shares)	1,061,260	1,636,016	2,741,854
Options exercisable, end of fiscal year, Options (in shares)	352,829	369,015	223,869
Weighted Average Exercise Price Activity
Outstanding, beginning of fiscal year, Price (in dollars per share)	$ 3.61	$ 3.44	$ 0.00
Granted, Price (in dollars per share)	0.54	0.00	3.28
Exercised, Price (in dollars per share)	3.27	2.24	0.99
Forfeited, Price (in dollars per share)	5.69	4.64	3.75
Outstanding, end of fiscal year, Price (in dollars per share)	3.55	3.61	3.44
Options exercisable, end of fiscal year, Price (in dollars per share)	$ 5.11	$ 5.00	$ 4.95