Segment Information - Net Sales to Unaffiliated Customers by Geographic Area (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
Revenues from External Customers and Long-Lived Assets [Line Items]
Total	$ 23,739	$ 22,111	$ 23,098	$ 19,548	$ 25,359	$ 24,549	$ 26,369	$ 23,714	$ 88,496	$ 99,991	$ 105,498
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total									65,386	85,406	96,132
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total									$ 23,110	$ 14,585	$ 9,366