EMPLOYEE BENEFIT PLANS (Details)		12 Months Ended
	May. 23, 2016 USD ($) shares	Mar. 31, 2017 USD ($) Employee $ / shares shares	Mar. 31, 2016 USD ($) Plans Objectives Age $ / shares shares	Mar. 31, 2015 USD ($) Employee $ / shares shares	Mar. 31, 2014 USD ($) Contract $ / shares	May. 14, 2013 shares
Compensation Related Costs [Line Items]
Defined contribution pension match			3.00%
Defined contribution pension			3.00%
Defined contribution amount			$ 22,200,000	$ 15,200,000	$ 12,700,000
Pension plan investment strategy, number of objectives | Objectives			3
Change in benefit obligation:
Projected benefit obligation (PBO) at beginning of period		$ 525,053,000	$ 639,299,000	637,641,000
Service cost for benefits earned during the period			8,243,000	7,878,000	7,886,000
Interest cost on PBO			20,108,000	26,000,000	26,861,000
Actuarial loss (gain)			(17,096,000)	86,940,000
Benefit payments and expenses			(29,836,000)	(28,191,000)
Curtailments			(12,960,000)	0
Settlements			(65,799,000)	0
Effect of exchange rate changes			(16,906,000)	(90,969,000)
Projected benefit obligation (PBO) at end of period			525,053,000	639,299,000	637,641,000
Change in plan assets:
Market value of assets at beginning of period		$ 454,946,000	539,723,000	550,818,000
Actual return on assets			(6,271,000)	57,691,000
Employer contributions			32,128,000	34,633,000
Benefit payments and expenses			(29,836,000)	(28,191,000)
Settlements			(65,799,000)	0
Effect of exchange rate changes			(14,999,000)	(75,228,000)
Market value of assets at end of period			454,946,000	539,723,000	550,818,000
Reconciliation of funded status:
Accumulated benefit obligation (ABO)			524,540,000	615,136,000
Net recognized pension liability			70,107,000	99,576,000
Amounts recognized in accumulated other comprehensive loss			235,720,000	252,920,000
Components of net periodic pension cost
Service cost for benefits earned during the period			8,243,000	7,878,000	7,886,000
Interest cost on PBO			20,108,000	26,000,000	26,861,000
Expected return on assets			(27,208,000)	(31,020,000)	(29,282,000)
Amortization of unrecognized losses			8,246,000	6,653,000	7,705,000
Net periodic pension cost			9,389,000	$ 9,511,000	13,170,000
Amount in accumulated OCI expected to be recognized in following fiscal year			$ 6,800,000
Defined benefit plan, assets, target allocations
Target allocation of plan assets			100.00%	100.00%
Actual allocation of plan assets			100.00%	100.00%
Projected benefit payments by year
2017			$ 22,468,000
2018			22,997,000
2019			23,572,000
2020			24,003,000
2021			24,578,000
Aggregate 2022 - 2025			$ 131,082,000
Incentive Compensation
Common Stock shares reserved | shares			3,950,524
Number of shares available for grant | shares			1,468,226
Stock-based compensation expense			$ 21,181,000	$ 16,353,000	15,433,000
Options, outstanding, weighted average exercise price, beginning balance | $ / shares		$ 57.74	$ 57.80
Options, grants in period, weighted average exercise price | $ / shares			57.52
Options, exercises in period, weighted average exercise price | $ / shares			0.00	$ 45.31
Options, expired or forfeited in period, weighted average exercise price | $ / shares			54.94
Options, outstanding, weighted average exercise price, ending balance | $ / shares			57.74	$ 57.80
Options, exercisable, weighted average exercise price | $ / shares			$ 53.40
Options, outstanding, number, beginning balance | shares		2,041,442	1,336,136
Options, grants in period | shares			740,718
Options, exercises in period | shares			0	114,145
Options, expired or forfeited in period | shares			35,412
Options, outstanding, number, ending balance | shares			2,041,442	1,336,136
Options, exercisable | shares			1,057,607
Options, exercisable, weighted average remaining contractual term			4 years 10 months 5 days
Options, outstanding, weighted average remaining contractual term			6 years 9 months
Options, outstanding, intrinsic value			$ 0
Options, exercisable, intrinsic value			0
Tax benefit attributable to options exercised			$ 0	$ 1,600,000	5,700,000
Non-vested Restricted Stock, nonvested, number, beginning balance | shares		440,856	419,229
Non-vested Restricted Stock, grants in period | shares			213,349
Non-vested Restricted Stock, vested in period | shares			182,484
Non-vested Restricted Stock, forfeited in period | shares			9,238
Non-vested Restricted Stock, nonvested, number, ending balance | shares			440,856	419,229
Non-vested Restricted Stock, weighted average grant date fair value, beginning balance | $ / shares		$ 65.24	$ 62.81
Non-vested Restricted Stock, grants in period, weighted average grant date fair value | $ / shares			56.76
Non-vested Restricted Stock, forfeited in period, weighted average grant date fair value | $ / shares			65.62
Non-vested Restricted Stock, vested in period, weighted average grant date fair value | $ / shares			49.72
Non-vested Restricted Stock, weighted average grant date fair value, ending balance | $ / shares			$ 65.24	$ 62.81
Cash Bonus				$ 19,900,000	17,200,000
Contributions to deferred compensation plan			$ 1,300,000	1,500,000	900,000
Americas
Incentive Compensation
Severance cost				$ 900,000	2,900,000
Southern North Sea
Incentive Compensation
Severance cost					$ 2,100,000
Number of terminated contracts | Contract					2
Voluntary separation program
Incentive Compensation
Voluntary separation program, number of employees offered | Employee				2,888
Voluntary separation program, number of employees acceptance | Employee				137
Severance cost			8,600,000
Voluntary separation program | Direct cost
Incentive Compensation
Severance cost			7,700,000
Voluntary separation program | General administrative expense
Incentive Compensation
Severance cost			900,000
Involuntary separation program
Incentive Compensation
Severance cost			13,900,000
Involuntary separation program | Africa
Incentive Compensation
Severance cost				$ 900,000
Involuntary separation program | Direct cost
Incentive Compensation
Severance cost			5,100,000
Involuntary separation program | General administrative expense
Incentive Compensation
Severance cost			8,800,000
Fair value, measurements, recurring
Incentive Compensation
Rabbi Trust investments			$ 2,990,000	$ 2,379,000
Stock options
Incentive Compensation
Award requisite service period			3 years
Fair value assumptions, risk free interest rate			1.62%	1.67%	1.00%
Fair value assumptions, expected life (years)			5 years	5 years	5 years
Fair value assumptions, volatility			28.10%	30.10%	48.70%
Fair value assumptions, dividend yield			3.14%	2.06%	1.60%
Weighted average grant-date fair value of options granted | $ / shares			$ 10.71	$ 17.17	$ 23.77
Share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition			1 year 8 months
Share-based compensation, nonvested awards, number of shares | shares			983,835
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value			$ 0	$ 2,400,000	$ 15,500,000
Share-based compensation vested awards fair value			7,400,000	8,900,000	5,100,000
Employee service share-based compensation, cash received from exercise of stock options			0	5,200,000	15,400,000
Tax benefit attributable to options exercised			0	600,000	5,400,000
Share-based compensation, nonvested awards, compensation cost can't yet recognized			$ 7,600,000
Restricted stock and restricted stock units
Incentive Compensation
Award requisite service period			3 years
Stock-based compensation expense			$ 12,900,000	10,100,000	9,400,000
Share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition			1 year 8 months
Share-based compensation, nonvested awards, number of shares | shares			440,856
Share-based compensation, nonvested awards, compensation cost can't yet recognized			$ 11,100,000
Performance cash
Incentive Compensation
Award requisite service period			3 years
Performance cash max payout			$ 14,000,000	13,800,000	12,200,000
Performance cash compensation expense			$ 1,400,000	$ 14,100,000	$ 8,700,000
Performance cash | Maximum
Incentive Compensation
Performance cash, percentage of target amount			200.00%
Performance cash | Minimum
Incentive Compensation
Performance cash, percentage of target amount			0.00%
Plan 2007
Incentive Compensation
Common Stock shares reserved | shares			5,400,000			2,400,000
Common Stock award, maximum | shares			500,000
Reduction from a full value share granted, number of shares | shares			2
Reduction from an option and stock appreciation right granted, number of shares | shares			1
Plan 2007 | 2007 Plan Amendment [Member] | Subsequent event
Incentive Compensation
Common Stock, shares reserved for issuance | shares	6,400,000
Common Stock, full value shares reserved | shares	3,200,000
Common Stock, additional capital shares reserved for future issuance | shares	5,250,000
Common Stock, additional full value shares reserved for future issuance | shares	2,625,000
Common Stock award, maximum | shares	1,000,000
Number of shares considered, stock option and stock appreciation right granted | shares	1
Number of shares considered, stock option and stock appreciation right settled | shares	2
Total compensation expense authorized for non-employee directors	$ 1,125,000
Plan 2007 | Stock options
Incentive Compensation
Stock options, expiration period			10 years
Options, grants in period, weighted average exercise price | $ / shares			$ 58.17	$ 74.37	$ 62.66
Plan 2004 | Stock options
Incentive Compensation
Stock options, expiration period			10 years
Original terms
Incentive Compensation
Retirement terms, years of service			5 years
Retirement terms, retirement age			62 years
First amendment
Incentive Compensation
Retirement terms, years of service and retirement age			80 years
Share-based compensation award, tranche one | Stock options
Incentive Compensation
Award vesting rights, percentage			33.00%
Share-based compensation award, tranche two | Stock options
Incentive Compensation
Award vesting rights, percentage			33.00%
Share-based compensation award, tranche three | Stock options
Incentive Compensation
Award vesting rights, percentage			33.00%
Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		$ 14,229,000	$ 13,657,000
Market value of assets at end of period			14,229,000	$ 13,657,000
Fair value, inputs, Level 1 | Fair value, measurements, recurring
Incentive Compensation
Rabbi Trust investments			2,990,000	2,379,000
Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		438,233,000	470,139,000
Market value of assets at end of period			438,233,000	470,139,000
Fair value, inputs, Level 2 | Fair value, measurements, recurring
Incentive Compensation
Rabbi Trust investments			0	0
Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		2,484,000	55,927,000
Actual return on assets			3,132,000
Net purchases, sales and settlements			(56,859,000)
Effect of exchange rate changes			284,000
Market value of assets at end of period			2,484,000	55,927,000
Fair value, inputs, Level 3 | Fair value, measurements, recurring
Incentive Compensation
Rabbi Trust investments			$ 0	$ 0
Equity securities
Defined benefit plan, assets, target allocations
Target allocation of plan assets			58.30%	58.30%
Actual allocation of plan assets			60.70%	57.10%
Debt securities
Defined benefit plan, assets, target allocations
Target allocation of plan assets			31.10%	31.10%
Actual allocation of plan assets			35.90%	35.80%
Property
Defined benefit plan, assets, target allocations
Target allocation of plan assets			0.00%	0.00%
Actual allocation of plan assets			0.10%	1.60%
Other assets
Defined benefit plan, assets, target allocations
Target allocation of plan assets			10.60%	10.60%
Actual allocation of plan assets			3.30%	5.50%
Cash and cash equivalents
Change in plan assets:
Market value of assets at beginning of period		14,229,000	$ 13,657,000
Market value of assets at end of period			14,229,000	$ 13,657,000
Cash and cash equivalents | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		14,229,000	13,657,000
Market value of assets at end of period			14,229,000	13,657,000
Cash and cash equivalents | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Cash and cash equivalents | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Equity investments - U.K.
Change in plan assets:
Market value of assets at beginning of period		61,085,000	104,953,000
Market value of assets at end of period			61,085,000	104,953,000
Equity investments - U.K. | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Equity investments - U.K. | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		61,085,000	104,953,000
Market value of assets at end of period			61,085,000	104,953,000
Equity investments - U.K. | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Equity investments - Non-U.K.
Change in plan assets:
Market value of assets at beginning of period		117,140,000	98,867,000
Market value of assets at end of period			117,140,000	98,867,000
Equity investments - Non-U.K. | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Equity investments - Non-U.K. | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		117,140,000	98,867,000
Market value of assets at end of period			117,140,000	98,867,000
Equity investments - Non-U.K. | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Diviersified growth (absolute return) funds
Change in plan assets:
Market value of assets at beginning of period		98,024,000	101,242,000
Market value of assets at end of period			98,024,000	101,242,000
Diviersified growth (absolute return) funds | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Diviersified growth (absolute return) funds | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		98,024,000	101,242,000
Market value of assets at end of period			98,024,000	101,242,000
Diviersified growth (absolute return) funds | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Government debt securities
Change in plan assets:
Market value of assets at beginning of period		72,728,000	71,998,000
Market value of assets at end of period			72,728,000	71,998,000
Government debt securities | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Government debt securities | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		72,728,000	71,998,000
Market value of assets at end of period			72,728,000	71,998,000
Government debt securities | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Corporate debt securities
Change in plan assets:
Market value of assets at beginning of period		89,256,000	93,079,000
Market value of assets at end of period			89,256,000	93,079,000
Corporate debt securities | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Corporate debt securities | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		89,256,000	93,079,000
Market value of assets at end of period			89,256,000	93,079,000
Corporate debt securities | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Insurance policies
Change in plan assets:
Market value of assets at beginning of period		2,484,000	55,927,000
Market value of assets at end of period			2,484,000	55,927,000
Insurance policies | Fair value, inputs, Level 1
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Insurance policies | Fair value, inputs, Level 2
Change in plan assets:
Market value of assets at beginning of period		0	0
Market value of assets at end of period			0	0
Insurance policies | Fair value, inputs, Level 3
Change in plan assets:
Market value of assets at beginning of period		2,484,000	55,927,000
Market value of assets at end of period			$ 2,484,000	55,927,000
Chief Executive Officer
Incentive Compensation
Severance cost				5,500,000
Officers
Incentive Compensation
Severance cost				$ 5,500,000	$ 2,900,000
Officers | Subsequent event
Incentive Compensation
Severance cost		$ 4,000,000
Number of other employee departure | Employee		2
Non-employee directors | Plan 2003
Incentive Compensation
Common Stock shares reserved | shares			250,000
Stock options, grants in period, net of forfeitures | shares			5,000
Non-employee directors | Plan 2003 | Stock options
Incentive Compensation
Stock options, expiration period			10 years
Award requisite service period			6 months
Pension plan | U.K. pension plan
Compensation Related Costs [Line Items]
Annual rate increase limit			5.00%
Number of original closed defined benefit pension plans | Plans			2
Minimum contribution match			5.00%
Number of other defined contribution plans | Plans			3
Number of other defined contribution plans closed to new members | Plans			2
Estimated cash contributions			$ 17,800,000
Assumptions used
Discount rate			3.30%	4.40%	4.40%
Expected return on plan assets			5.40%	6.29%	6.29%
Pension increase rate			2.80%	3.10%	3.30%
Pension plan | U.K. pension plan | Pilot
Compensation Related Costs [Line Items]
Closed plan maximum contribution			7.35%
Pension plan | U.K. pension plan | Other employee
Compensation Related Costs [Line Items]
Closed plan maximum contribution			7.00%
Pension plan | Norway pension plan
Assumptions used
Discount rate			2.50%	4.25%	4.00%
Rate of compensation increase			3.50%	4.00%	4.25%
Social security increase amount			3.25%	3.75%	4.00%
Expected return on plan assets			1.50%	2.75%	3.25%
Pension increase rate			0.00%	1.75%	1.25%
Pension plan | Norway pension plan | Minimum
Compensation Related Costs [Line Items]
Years of service for maximum pension | Age			30
Pension plan | Norway pension plan | Pilot
Compensation Related Costs [Line Items]
Retirement age | Age			58
Pension plan | Norway pension plan | Other employee
Compensation Related Costs [Line Items]
Retirement age | Age			62