Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 1,807	$ 2,474	$ 1,937
Charged to Costs and Expenses	2,043	1,723	529
Charged to Other Accounts	(105)	(8)	4
Inventory write off	(898)	(2,382)	4
Balance at end of year	2,847	1,807	2,474
Valuation Allowance of Deferred Tax Assets
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	2,199		3,702
Charged to Other Accounts	16,674		(1,503)
Inventory write off	(836)
Balance at end of year	18,037		2,199
Inventory Valuation Reserve
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	2,933	2,185	1,127
Charged to Costs and Expenses	2,204	779	1,307
Charged to Other Accounts	(181)	(25)	(34)
Inventory write off	(154)	(6)	(215)
Balance at end of year	$ 4,802	$ 2,933	$ 2,185