Summary of Significant Accounting Policies - Compensation Expense and Related Tax Benefit for Equity Based Payments (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation expense	$ 13,109	$ 14,727	$ 13,107
Income tax benefit	4,531	5,132	4,522
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation expense	871	1,061	1,029
Selling and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation expense	2,100	1,792	1,463
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation expense	1,616	1,593	1,387
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation expense	$ 8,522	$ 10,281	$ 9,228