Commitments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Commitments And Contingencies Disclosure [Line Items]
Rent expense	$ 0.5	$ 0.6	$ 1.5	$ 1.7
Minimum
Commitments And Contingencies Disclosure [Line Items]
Term of warranties on certain product sales			12 months
Maximum
Commitments And Contingencies Disclosure [Line Items]
Term of warranties on certain product sales			24 months