Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valuation Account for Accounts Receivable [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 1,560	$ 1,459	$ 1,406
Charged to Costs and Expenses	0	343	315
Deductions / (Recoveries)	891	242	262
Balance at End of Period	669	1,560	1,459
Valuation Accounts for Inventories [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	14,710	9,837	9,054
Charged to Costs and Expenses	6,758	8,762	5,470
Deductions / (Recoveries)	7,813	3,889	4,687
Balance at End of Period	$ 13,655	$ 14,710	$ 9,837