Stock-Based Compensation (Tables)

6 Months Ended

Sep. 30, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Recognized

The following table summarizes stock-based compensation expense by financial statement line item in the Company’s condensed consolidated statements of operations for the three and six months ended September 30, 2019 and 2018:

	For the Three Months Ended September 30,				For the Six Months Ended September 30,
		2019		2018		2019		2018
	(in $000's)
Cost of product revenue	$	881	$	774	$	1,722	$	1,349
Research and development		1,823		2,618		3,706		4,584
Selling, general and administrative		10,619		12,542		21,017		22,246
	$	13,323	$	15,934	$	26,445	$	28,179

Summary of Stock Option Activity

The following table summarizes the stock option activity for the six months ended September 30, 2019:

						Weighted
				Weighted		Average		Aggregate
				Average		Remaining		Intrinsic
	Options			Exercise		Contractual		Value
	(in thousands)			Price		Term (years)		(in thousands)
Outstanding at beginning of period		853		$	87.14		5.57
Granted		107			264.56
Exercised		(58	)		47.01
Cancelled and expired		(12	)		231.53
Outstanding at end of period		890		$	109.03		5.68	$	85,789
Exercisable at end of period		667		$	61.69		4.64	$	82,730
Options vested and expected to vest at end of period		886		$	109.06		5.68	$	85,484

Summary of Weighted Average Grant-Date Fair Values And Weighted Average Assumptions Used to Calculate Fair Value of Options Granted

The weighted average grant-date fair values and weighted average assumptions used in the calculation of fair value of options granted during the three and six months ended September 30, 2019 and 2018 was as follows:

	For the Three Months Ended September 30,						For the Six Months Ended September 30,
		2019			2018			2019			2018
Weighted average grant-date fair value	$	70.40		$	148.51		$	95.62		$	142.81
Valuation assumptions:
Risk-free interest rate		1.54	%		2.87	%		2.02	%		2.93	%
Expected option life (years)		4.13			3.99			4.14			4.04
Expected volatility		44.24	%		43.9	%		42.34	%		42.7	%

Summary of Restricted Stock Units Activity

The following table summarizes activity of restricted stock units for the six months ended September 30, 2019:

	Number of Shares			Weighted Average Grant Date Fair Value
	(in thousands)			(per share)
Restricted stock units at beginning of period		620		$	193.53
Granted		155			258.07
Vested		(385	)		144.16
Forfeited		(59	)		309.74
Restricted stock units at end of period		331		$	261.95