STOCK BASED COMPENSATION - Expense Resulting from Stock Option Awards and ESPP (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 17,773	$ 17,457	$ 16,339
Stock Options [Member] | Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	52	120	136
Stock Options [Member] | Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	15,214	15,212	13,630
Restricted Stock Units (RSUs) [Member] | Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,267	1,116	1,474
ESPP shares [Member] | Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,240	$ 1,009	$ 1,099