Share-Based Compensation

9 Months Ended

Sep. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

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



	Three Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
Selling, general and administrative	$	18,978		$	20,903		$	57,012		$	61,582
Research and development	4,600			4,650			13,684			13,651
Cost of product sales	1,525			1,573			5,022			4,346
Total share-based compensation expense, pre-tax	25,103			27,126			75,718			79,579
Income tax benefit from share-based compensation expense	(3,552		)	(6,354		)	(12,066		)	(23,816		)
Total share-based compensation expense, net of tax	$	21,551		$	20,772		$	63,652		$	55,763

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 September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
Shares underlying options granted (in thousands)	117			87			1,349			1,343
Grant date fair value	$	53.93		$	45.87		$	46.95		$	42.69
Black-Scholes option pricing model assumption information:
Volatility	32		%	35		%	35		%	35		%
Expected term (years)	4.5			4.3			4.5			4.3
Range of risk-free rates	2.7-2.8%			1.6-1.8%			2.2-2.8%			1.6-1.8%
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 September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
RSUs granted (in thousands)	71		35		564		537
Grant date fair value	$	174.73	$	148.60	$	145.59	$	137.23

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 September 30, 2018, compensation cost not yet recognized related to unvested share options and RSUs was $82.8 million and $102.7 million, respectively, which is expected to be recognized over a weighted-average period of 2.7 years and 2.6 years, respectively.