STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2018

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

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense related to awards issued under the Company's incentive compensation plans for the three and six months ended June 30, 2018 and 2017 was as follows (in millions):



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Cost of sales	$	2.8	$	2.3	$	5.8	$	4.6
Selling, general, and administrative expenses	12.7		10.0		24.5		20.2
Research and development expenses	3.7		3.0		7.3		5.7
Total stock-based compensation expense	$	19.2	$	15.3	$	37.6	$	30.5

Schedule of Weighted-Average Assumptions for Options Granted

The following table includes the weighted-average grant-date fair values of stock options granted during the periods indicated and the related weighted-average assumptions used in the Black-Scholes option pricing model:



Option Awards	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Average risk-free interest rate	2.9		%	1.8		%	2.9		%	1.8		%
Expected dividend yield	None			None			None			None
Expected volatility	29.0		%	33.0		%	29.1		%	33.0		%
Expected term (years)	5.0			4.5			5.0			4.5
Fair value, per option	$	42.12		$	33.64		$	42.14		$	33.54

Schedule of Weighted-Average Assumptions for ESPP Subscriptions Granted

The following table includes the weighted-average grant-date fair values for ESPP subscriptions granted during the periods indicated and the related weighted-average assumptions used in the Black-Scholes option pricing model:



ESPP	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Average risk-free interest rate	1.0		%	0.5		%	0.9		%	0.4		%
Expected dividend yield	None			None			None			None
Expected volatility	32.8		%	32.8		%	32.6		%	32.9		%
Expected term (years)	0.6			0.6			0.6			0.6
Fair value, per share	$	36.94		$	29.89		$	35.49		$	25.19