SHARE-BASED COMPENSATION - Other Equity Awards Activity (Details) - $ / shares	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Share bonus awards
Share-based compensation
Unvested share bonus targeted number of awards, beginning of period (in shares)	15,698,582	17,000,076	18,993,252
Granted (in shares)	6,155,761	8,261,666	7,619,722
Vested (in shares)	(6,473,562)	(8,606,246)	(8,529,378)
Forfeited (in shares)	(1,488,739)	(956,914)	(1,083,520)
Unvested share bonus targeted number of awards, end of period (in shares)	13,892,042	15,698,582	17,000,076
Unvested share bonus awards, weighted average grant-date fair value, end of period (in dollars per share)	$ 12.44	$ 10.77	$ 9.01
Granted, weighted average grant-date fair value (in dollars per share)	16.99	13.46	12.23
Vested, weighted average grant-date fair value (in dollars per share)	12.17	9.44	7.93
Forfeited, weighted average grant-date fair value (in dollars per share)	13.38	11.20	9.67
Unvested share bonus awards, weighted average grant-date fair value, end of period (in dollars per share)	$ 14.52	$ 12.44	$ 10.77
Share Bonus Awards with Market Conditions
Share-based compensation
Unvested share bonus targeted number of awards, end of period (in shares)	1,950,072
Share Bonus Awards with Market Conditions \| Fiscal Year 2018
Share-based compensation
Unvested share bonus targeted number of awards, end of period (in shares)	623,620
Granted, weighted average grant-date fair value (in dollars per share)	$ 20.25
Share Bonus Awards with Market Conditions \| Fiscal 2017
Share-based compensation
Granted (in shares)	700,000.0
Unvested share bonus targeted number of awards, end of period (in shares)	677,523
Granted, weighted average grant-date fair value (in dollars per share)	$ 17.57
Share Bonus Awards with Market Conditions \| Fiscal 2016
Share-based compensation
Unvested share bonus targeted number of awards, end of period (in shares)	648,929
Granted, weighted average grant-date fair value (in dollars per share)	$ 14.96
Share Bonus Awards with Market Conditions \| Minimum \| Fiscal Year 2018
Share-based compensation
Range of shares that may be issued (shares)	0
Share Bonus Awards with Market Conditions \| Minimum \| Fiscal 2017
Share-based compensation
Award vesting rights percentage	0.00%
Range of shares that may be issued (shares)	0
Share Bonus Awards with Market Conditions \| Minimum \| Fiscal 2016
Share-based compensation
Award vesting rights percentage	0.00%
Range of shares that may be issued (shares)	0
Share Bonus Awards with Market Conditions \| Minimum \| Fiscal 2015
Share-based compensation
Award vesting rights percentage	0.00%
Share Bonus Awards with Market Conditions \| Maximum
Share-based compensation
Range of shares that may be issued (shares)	3,900,144
Share Bonus Awards with Market Conditions \| Maximum \| Fiscal Year 2018
Share-based compensation
Range of shares that may be issued (shares)	1,247,240
Share Bonus Awards with Market Conditions \| Maximum \| Fiscal 2017
Share-based compensation
Award vesting rights percentage	200.00%
Range of shares that may be issued (shares)	1,355,046
Share Bonus Awards with Market Conditions \| Maximum \| Fiscal 2016
Share-based compensation
Award vesting rights percentage	200.00%
Range of shares that may be issued (shares)	1,297,858
Share Bonus Awards with Market Conditions \| Maximum \| Fiscal 2015
Share-based compensation
Award vesting rights percentage	200.00%
2010 Equity Incentive Plan \| Share Bonus Awards with Market Conditions \| Fiscal 2017
Share-based compensation
Granted (in shares)		1,700,000.0
2014 NEXTracker Equity Incentive Plan \| Share bonus awards
Share-based compensation
Unvested share bonus targeted number of awards, beginning of period (in shares)	1,543,437	2,309,096	0
Granted (in shares)	524,978	0	2,393,195
Vested (in shares)	(471,831)	(705,738)	(31,925)
Forfeited (in shares)	(868,934)	(59,921)	(52,174)
Unvested share bonus targeted number of awards, end of period (in shares)	727,650	1,543,437	2,309,096
Unvested share bonus awards, weighted average grant-date fair value, end of period (in dollars per share)	$ 10.23	$ 10.27	$ 0.00
Granted, weighted average grant-date fair value (in dollars per share)	16.73	0.00	10.27
Vested, weighted average grant-date fair value (in dollars per share)	7.63	10.19	10.27
Forfeited, weighted average grant-date fair value (in dollars per share)	10.18	10.27	10.27
Unvested share bonus awards, weighted average grant-date fair value, end of period (in dollars per share)	$ 11.85	$ 10.23	$ 10.27

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 718
-SubTopic 10
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-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of share instruments newly issued under a share-based compensation plan.

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Percentage of vesting of share-based compensation awards.

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