Segment Data (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Deferred finance cost amortization expense	$ 308,000	$ 153,000	$ 17,000
Net receipt of import duties	13,000	115,000	32,000
Capital expenditures included in current liabilities	$ 828,000	$ 7,690,000	$ 578,000