STOCK BASED COMPENSATION - Stock-Based Compensation Expense Resulting from Stock Option Awards, RSUs, PSUs and ESPP (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 21.3	$ 20.5	$ 21.7
Stock Options | Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	14.7	17.4	18.6
Restricted Stock Units (RSUs) | Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	5.2	0.9	1.5
Performance-Based Restricted Stock Units | Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	0.2	0.0	0.0
ESPP | Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1.2	$ 2.2	$ 1.6