Common Stock and Stock Plans (Tables)

12 Months Ended

Mar. 31, 2019

Equity [Abstract]

Summary of Stock-based Compensation Expense

Total stock-based compensation expense recognized in accordance with the authoritative guidance for share-based payments was as follows:

	Fiscal Years Ended
	March 31, 2019			March 31, 2018			March 31, 2017
	(In thousands)
Stock-based compensation expense before taxes	$	79,599		$	68,545		$	55,775
Related income tax benefits		(18,824	)		(16,278	)		(21,057	)
Stock-based compensation expense, net of taxes	$	60,775		$	52,267		$	34,718

Summary of Employee Stock Options and Employee Stock Purchase Plan Weighted Average Assumptions

The weighted average assumptions (annualized percentages) used in the Black-Scholes model and Monte Carlo simulation were as follows:

	Employee Stock Options									TSR Performance Stock Options						Employee Stock Purchase Plan
	Fiscal Year 2019			Fiscal Year 2018			Fiscal Year 2017			Fiscal Year 2019			Fiscal Year 2018 *			Fiscal Year 2019			Fiscal Year 2018			Fiscal Year 2017
Volatility		27.9	%		30.4	%		33.4	%		28.2	%		27.5	%		32.8	%		22.0	%		31.1	%
Risk-free interest rate		2.8	%		1.9	%		1.7	%		2.8	%		1.9	%		2.4	%		1.3	%		0.5	%
Dividend yield		0.0	%		0.0	%		0.0	%		0.0	%		0.0	%		0.0	%		0.0	%		0.0	%
Expected life	5.0 years			5.4 years			5.5 years			5.0 years			5.0 years			0.5 years			0.5 years			0.5 years

* The Company began granting TSR performance stock options to executive officers in the third quarter of fiscal year 2018.

Summary of Employee Stock Option Activity and TSR Performance Stock Option Activity

A summary of employee stock option activity for fiscal year 2019 is presented below:

	Number of Shares			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term in Years		Aggregate Intrinsic Value (In thousands)
Outstanding at March 31, 2018		1,766,500		$	61.13
Options granted		40,000			61.60
Options canceled		—			—
Options exercised		(275,000	)		40.32
Outstanding at March 31, 2019		1,531,500		$	64.87		2.55	$	19,337
Vested and exercisable at March 31, 2019		1,164,250		$	64.34		2.22	$	15,321

A summary of TSR performance stock option activity for fiscal year 2019 is presented below:

	Number of Shares (1)		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term in Years		Aggregate Intrinsic Value (In thousands)
Outstanding at March 31, 2018		497,500	$	73.77
TSR performance options granted		530,000		69.05
TSR performance options canceled		—		—
TSR performance options exercised		—		—
Outstanding at March 31, 2019		1,027,500	$	71.34		5.15	$	6,334
Vested and exercisable at March 31, 2019		—	$	—		—	$	—

(1) Number of shares is based on the target number of options under each TSR performance stock option.

Summary of Restricted Stock Unit Activity

A summary of restricted stock unit activity for fiscal year 2019 is presented below:

	Number of Restricted Stock Units			Weighted Average Grant Date Fair Value per Share
Outstanding at March 31, 2018		2,862,194		$	67.64
Awarded		1,321,914			67.88
Forfeited		(78,364	)		69.19
Released		(1,201,502	)		66.98
Outstanding at March 31, 2019		2,904,242		$	67.99
Vested and deferred at March 31, 2019		173,334		$	42.59