Warranty Reserve - Summary of Warranty Reserve Activity Included in Accounts Payable and Accrued Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Guarantees [Abstract]
Balance at beginning of period	$ 1,012	$ 988	$ 963	$ 1,009
Additions	90	18	174	45
Releases and/or charges incurred	(418)	(26)	(453)	(74)
Balance at end of period	$ 684	$ 980	$ 684	$ 980