SHARE-BASED COMPENSATION (Tables)

12 Months Ended

Mar. 31, 2019

Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]

Schedule of share-based compensation expense

The following table summarizes the Company's share-based compensation expense for all Equity Incentive Plans:

	Fiscal Year Ended March 31,
	2019		2018		2017
	(In thousands)
Cost of sales	$	19,554	$	19,102	$	10,023
Selling, general and administrative expenses	56,478		66,142		72,243
Total share-based compensation expense	$	76,032	$	85,244	$	82,266

Schedule of weighted-average assumptions

The fair value of the Company's restricted share unit awards under the 2017 Plan, whereby vesting is contingent on meeting certain market conditions, for fiscal years 2019, 2018, and 2017 was estimated using the following weighted-average assumptions:

	Fiscal Year Ended March 31,
	2019		2018		2017
Expected volatility	27.4	%	25.1	%	25.8	%
Average peer volatility	25.6	%	28.7	%	25.1	%
Average peer correlation	0.5		0.6		0.6
Expected dividends	0.0	%	0.0	%	0.0	%
Risk-free interest rate	2.7	%	1.5	%	0.9	%

Summary of option activity

The following is a summary of option activity for all plans ("Price" reflects the weighted-average exercise price):

	Fiscal Year Ended March 31,
	2019				2018				2017
	Options		Price		Options		Price		Options		Price
Outstanding, beginning of fiscal year	1,189,550		$	3.28	1,937,400		$	3.75	5,111,490		$	5.70
Granted	—		—		288,386		0.54		159,057		0.51
Exercised	(244,393	)	1.00		(667,184	)	4.15		(2,283,201	)	5.44
Forfeited	(71,927	)	3.37		(369,052	)	5.75		(1,049,946	)	9.47
Outstanding, end of fiscal year	873,230		$	3.93	1,189,550		$	3.28	1,937,400		$	3.75
Options exercisable, end of fiscal year	546,339		$	5.34	373,950		$	4.99	507,965		$	6.08

Schedule of share bonus award activity

The following table summarizes the Company's restricted share unit award activity under all plans ("Price" reflects the weighted-average grant-date fair value):

	Fiscal Year Ended March 31,
	2019				2018				2017
	Shares		Price		Shares		Price		Shares		Price
Unvested restricted share unit awards outstanding, beginning of fiscal year	14,619,692		$	14.39	17,242,019		$	12.24	19,309,172		$	10.71
Granted (1)	8,257,502		12.59		6,680,739		16.97		8,261,666		13.46
Vested (1)	(5,952,039	)	13.12		(6,945,393	)	11.86		(9,311,984	)	9.50
Forfeited	(2,021,269	)	14.51		(2,357,673	)	12.20		(1,016,835	)	11.15
Unvested restricted share unit awards outstanding, end of fiscal year	14,903,886		$	13.76	14,619,692		$	14.39	17,242,019		$	12.24

(1) Included in the fiscal years 2018 and 2017 amounts are 0.7 million and 1.7 million of restricted share unit awards, respectively, representing the number of awards achieved above target levels based on the achievement of certain market conditions, as further described in the table below. These awards were issued and immediately vested in accordance with the terms and conditions of the underlying awards.

Schedule of share bonus awards with market conditions

Of the 14.9 million unvested restricted share unit awards outstanding under all plans as of the fiscal year ended March 31, 2019, approximately 2.5 million unvested restricted share unit awards represent the target amount of grants made to certain key employees whereby vesting is contingent on meeting certain market conditions summarized as follows:

	Targeted number of awards as of March 31, 2019 (in shares)			Range of shares that may be issued (1)
		Average grant date fair value (per share)
						Assessment dates
Year of grant				Minimum	Maximum
Fiscal 2019	1,316,279	$	14.00	—	2,632,558	June 2021
Fiscal 2018	586,077	$	20.25	—	1,172,154	June 2020
Fiscal 2017	619,574	$	17.57	—	1,239,148	June 2019
Totals	2,521,930			—	5,043,860

(1) Vesting ranges from zero to 200% based on measurement of Flex's total shareholder return against the Standard and Poor's ("S&P") 500 Composite Index.