STOCK BASED COMPENSATION - Expense Resulting from Stock Option Awards and ESPP (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,452	$ 5,417	$ 11,557	$ 10,904
Stock Options [Member] | Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	12	22	27	45
Stock Options [Member] | Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	4,585	4,650	9,337	9,379
Restricted Stock Units (RSUs) [Member] | Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	399	375	958	721
ESPP [Member] | Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 456	$ 370	$ 1,235	$ 759