EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Mar. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of accumulated and projected benefit obligations

The following tables provide a rollforward of the projected benefit obligation and the fair value of plan assets, set forth the defined benefit retirement plans’ funded status and provide detail of the components of net periodic pension cost calculated for the U.K. and Norway pension plans. The measurement date adopted is March 31. For the purposes of amortizing gains and losses, the 10% corridor approach has been adopted and assets are taken at fair market value. Any such gains or losses are amortized over the average remaining life expectancy of the plan members.

	Fiscal Year Ended March 31,
	2016			2015
	(In thousands)
Change in benefit obligation:
Projected benefit obligation (PBO) at beginning of period	$	639,299		$	637,641
Service cost	8,243			7,878
Interest cost	20,108			26,000
Actuarial loss (gain)	(17,096		)	86,940
Benefit payments and expenses	(29,836		)	(28,191		)
Curtailments	(12,960		)	—
Settlements	(65,799		)	—
Effect of exchange rate changes	(16,906		)	(90,969		)
Projected benefit obligation (PBO) at end of period	$	525,053		$	639,299

Schedule of change in plan assets

The following tables provide a rollforward of the projected benefit obligation and the fair value of plan assets, set forth the defined benefit retirement plans’ funded status and provide detail of the components of net periodic pension cost calculated for the U.K. and Norway pension plans. The measurement date adopted is March 31. For the purposes of amortizing gains and losses, the 10% corridor approach has been adopted and assets are taken at fair market value. Any such gains or losses are amortized over the average remaining life expectancy of the plan members.

Change in plan assets:
Market value of assets at beginning of period	$	539,723		$	550,818
Actual return on assets	(6,271		)	57,691
Employer contributions	32,128			34,633
Benefit payments and expenses	(29,836		)	(28,191		)
Settlements	(65,799		)	—
Effect of exchange rate changes	(14,999		)	(75,228		)
Market value of assets at end of period	$	454,946		$	539,723

Schedule of net funded status

The following tables provide a rollforward of the projected benefit obligation and the fair value of plan assets, set forth the defined benefit retirement plans’ funded status and provide detail of the components of net periodic pension cost calculated for the U.K. and Norway pension plans. The measurement date adopted is March 31. For the purposes of amortizing gains and losses, the 10% corridor approach has been adopted and assets are taken at fair market value. Any such gains or losses are amortized over the average remaining life expectancy of the plan members.

Reconciliation of funded status:
Accumulated benefit obligation (ABO)	$	524,540		$	615,136
Projected benefit obligation (PBO)	$	525,053		$	639,299
Fair value of assets	(454,946		)	(539,723		)
Net recognized pension liability	$	70,107		$	99,576
Amounts recognized in accumulated other comprehensive loss	$	235,720		$	252,920

Schedule of components of net periodic pension cost

The following tables provide a rollforward of the projected benefit obligation and the fair value of plan assets, set forth the defined benefit retirement plans’ funded status and provide detail of the components of net periodic pension cost calculated for the U.K. and Norway pension plans. The measurement date adopted is March 31. For the purposes of amortizing gains and losses, the 10% corridor approach has been adopted and assets are taken at fair market value. Any such gains or losses are amortized over the average remaining life expectancy of the plan members.

	Fiscal Year Ended March 31,
	2016			2015			2014
	(In thousands)
Components of net periodic pension cost:
Service cost for benefits earned during the period	$	8,243		$	7,878		$	7,886
Interest cost on PBO	20,108			26,000			26,861
Expected return on assets	(27,208		)	(31,020		)	(29,282		)
Amortization of unrecognized losses	8,246			6,653			7,705
Net periodic pension cost	$	9,389		$	9,511		$	13,170

Schedule of assumptions

Actuarial assumptions used to develop the components of the U.K. plans were as follows:    

	Fiscal Year Ended March 31,
	2016		2015		2014
Discount rate	3.30	%	4.40	%	4.40	%
Expected long-term rate of return on assets	5.40	%	6.29	%	6.29	%
Pension increase rate	2.80	%	3.10	%	3.30	%

Actuarial assumptions used to develop the components of the Norway plan were as follows:

	Fiscal Year Ended March 31,
	2016		2015		2014
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	—	%	1.75	%	1.25	%

Schedule of investment strategy

The market value of the plan's assets as of March 31, 2016 and 2015 was allocated between asset classes as follows. Details of target allocation percentages under the Trustee’s investment strategies as of the same dates are also included.

	Target Allocation as of March 31,				Actual Allocation as of March 31,
Asset Category	2016		2015		2016		2015
Equity securities	58.3	%	58.3	%	60.7	%	57.1	%
Debt securities	31.1	%	31.1	%	35.9	%	35.8	%
Property	—	%	—	%	0.1	%	1.6	%
Other assets	10.6	%	10.6	%	3.3	%	5.5	%
Total	100.0	%	100.0	%	100.0	%	100.0	%

Schedule of fair value hierarchy

The following table summarizes, by level within the fair value hierarchy, the plan assets we had as of March 31, 2016, which are valued at fair value (in thousands):

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance as of March 31, 2016
Cash and cash equivalents	$	14,229	$	—	$	—	$	14,229
Equity investments - U.K.	—		61,085		—		61,085
Equity investments - Non-U.K.	—		117,140		—		117,140
Diversified growth (absolute return) funds	—		98,024		—		98,024
Government debt securities	—		72,728		—		72,728
Corporate debt securities	—		89,256		—		89,256
Insurance policies	—		—		2,484		2,484
Total investments	$	14,229	$	438,233	$	2,484	$	454,946

The following table summarizes, by level within the fair value hierarchy, the plan assets we had as of March 31, 2015, which are valued at fair value (in thousands):

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance at March 31, 2015
Cash and cash equivalents	$	13,657	$	—	$	—	$	13,657
Equity investments - U.K.	—		104,953		—		104,953
Equity investments - Non-U.K.	—		98,867		—		98,867
Diversified growth (absolute return) funds	—		101,242		—		101,242
Government debt securities	—		71,998		—		71,998
Corporate debt securities	—		93,079		—		93,079
Insurance policies	—		—		55,927		55,927
Total investments	$	13,657	$	470,139	$	55,927	$	539,723

Rollforward of Level 3 fair value changes

The following table summarizes the changes in the Level 3 plan assets for fiscal year 2016 (in thousands):

March 31, 2015	$	55,927
Actual return on assets	3,132
Net purchases, sales and settlements	(56,859		)
Effect of exchange rate changes	284
March 31, 2016	$	2,484

Future benefit payments

Estimated future benefit payments over each of the next five fiscal years from March 31, 2016 and in aggregate for the following five fiscal years after fiscal year 2021, including life assurance premiums, are as follows (in thousands):

Projected Benefit Payments by the Plans for Fiscal Years Ending March 31,	Payments
2017	$	22,468
2018	22,997
2019	23,572
2020	24,003
2021	24,578
Aggregate 2022 - 2025	131,082

Schedule of stock option activity

A summary of our stock option activity for fiscal year 2016 is presented below:

	Weighted Average Exercise Prices		Number of Shares		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value
						(in thousands)
Outstanding at March 31, 2015	$	57.80	1,336,136
Granted	57.52		740,718
Exercised	—		—
Expired or forfeited	54.94		(35,412	)
Outstanding at March 31, 2016	57.74		2,041,442		4.85	$	—
Exercisable at March 31, 2016	53.40		1,057,607		6.75	$	—

Schedule of Black Scholes assumptions

The following table shows the assumptions we used to compute the stock-based compensation expense for stock option grants issued during fiscal years 2016, 2015 and 2014.    

	Fiscal Year Ended March 31,
	2016			2015			2014
Risk free interest rate	1.62		%	1.67		%	1.0		%
Expected life (years)	5			5			5
Volatility	28.1		%	30.1		%	48.7		%
Dividend yield	3.14		%	2.06		%	1.60		%
Weighted average grant-date fair value of options granted	$	10.71		$	17.17		$	23.77

Schedule of non-vested restricted stock and restricted stock units

The following is a summary of non-vested restricted stock as of March 31, 2016 and 2015 and changes during fiscal year 2016:    

	Units		Weighted Average Grant Date Fair Value per Unit
Non-vested as of March 31, 2015	419,229		$	62.81
Granted	213,349		56.76
Forfeited	(9,238	)	65.62
Vested	(182,484	)	49.72
Non-vested as of March 31, 2016	440,856		65.24