Stock-Based Compensation (Tables)

3 Months Ended

Jun. 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 months ended June 30, 2019 and 2018:

	For the Three Months Ended June 30,
		2019		2018
	(in $000's)
Cost of product revenue	$	841	$	575
Research and development		1,883		1,966
Selling, general and administrative		10,397		9,704
	$	13,121	$	12,245

Summary of Stock Option Activity

The following table summarizes the stock option activity for the three months ended June 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		104			266.52
Exercised		(36	)		34.72
Cancelled and expired		(10	)		240.24
Outstanding at end of period		910		$	108.04		5.86	$	148,322
Exercisable at end of period		672		$	59.84		4.78	$	137,671
Options vested and expected to vest at end of period		904		$	108.10		5.85	$	147,284

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 months ended June 30, 2019 and 2018 was as follows:

	For the Three Months Ended June 30,
		2019			2018
Weighted average grant-date fair value	$	96.30		$	142.51
Valuation assumptions:
Risk-free interest rate		2.03	%		2.93	%
Expected option life (years)		4.14			4.04
Expected volatility		42.3	%		42.6	%

Summary of Restricted Stock Units Activity

The following table summarizes activity of restricted stock units for the three months ended June 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		145			262.71
Vested		(373	)		141.57
Forfeited		(54	)		316.58
Restricted stock units at end of period		338		$	262.47