Segment Information, Geographic Regions, and Major Customers - Reconciliation of Operating Segment Gross Profit to Consolidated Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Gross profit	$ 106,110	$ 97,213	$ 97,983	$ 93,860	$ 94,285	$ 83,077	$ 89,792	$ 87,667	$ 395,166	$ 354,821	$ 330,983
Operating Segment [Member]
Segment Reporting Information [Line Items]
Segment gross profit									396,983	356,014	332,647
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Stock-based compensation expense									$ (1,817)	$ (1,193)	$ (1,664)