Share-Based Compensation

3 Months Ended

Mar. 31, 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 March 31,
	2020			2019
Selling, general and administrative	$	20,596		$	20,370
Research and development	6,385			5,523
Cost of product sales	1,673			1,659
Total share-based compensation expense, pre-tax	28,654			27,552
Income tax benefit from share-based compensation expense	(3,746		)	(3,667		)
Total share-based compensation expense, net of tax	$	24,908		$	23,885

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 March 31,
	2020			2019
Shares underlying options granted (in thousands)	565			1,297
Grant date fair value	$	33.65		$	42.84
Black-Scholes option pricing model assumption information:
Volatility	32		%	32		%
Expected term (years)	4.6			4.5
Range of risk-free rates	0.8-1.6%			2.4-2.5%
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 March 31,
	2020		2019
RSUs granted (in thousands)	959		519
Grant date fair value	$	114.19	$	139.38

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 March 31, 2020, compensation cost not yet recognized related to unvested share options and RSUs was $82.5 million and $166.0 million, respectively, which is expected to be recognized over a weighted-average period of 2.7 years and 3.2 years, respectively.