Share-Based Compensation

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Share-based compensation expense related to share options, RSUs and grants under our ESPP was as follows (in thousands):



	Three Months Ended June 30,						Six Months Ended June 30,
	2020			2019			2020			2019
Selling, general and administrative	$	21,020		$	20,685		$	41,616		$	41,055
Research and development	7,663			5,896			14,048			11,419
Cost of product sales	1,921			1,708			3,594			3,367
Total share-based compensation expense, pre-tax	30,604			28,289			59,258			55,841
Income tax benefit from share-based compensation expense	(2,924		)	(4,473		)	(6,670		)	(8,140		)
Total share-based compensation expense, net of tax	$	27,680		$	23,816		$	52,588		$	47,701

Share Options

The table below shows the number of shares underlying options granted to purchase our ordinary shares, the weighted-average assumptions used in the Black-Scholes option pricing model and the resulting weighted-average grant date fair value of share options granted:



	Three Months Ended June 30,						Six Months Ended June 30,
	2020			2019			2020			2019
Shares underlying options granted (in thousands)	79			102			644			1,399
Grant date fair value	$	33.29		$	38.95		$	33.61		$	42.56
Black-Scholes option pricing model assumption information:
Volatility	36		%	31		%	32		%	32		%
Expected term (years)	4.6			4.5			4.6			4.5
Range of risk-free rates	0.3-0.4%			1.8-2.3%			0.3-1.6%			1.8-2.5%
Expected dividend yield	—		%	—		%	—		%	—		%

Restricted Stock Units

The table below shows the number of RSUs granted covering an equal number of our ordinary shares and the weighted-average grant date fair value of RSUs granted:



	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
RSUs granted (in thousands)	129		42		1,088		561
Grant date fair value	$	108.20	$	132.73	$	113.48	$	138.87

The fair value of RSUs is determined on the date of grant based on the market price of our ordinary shares on that date. The fair value of RSUs is expensed ratably over the vesting period, generally over four years.

As of June 30, 2020, compensation cost not yet recognized related to unvested share options and RSUs was $74.5 million and $159.4 million, respectively, which is expected to be recognized over a weighted-average period of 2.6 years and 3.0 years, respectively.