Global Thermoelectric Acquisition - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified			3 Months Ended	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Global Thermoelectric Inc	Jun. 30, 2014 Global Thermoelectric Inc
Business Acquisition [Line Items]
Product revenues			$ 8,174	$ 8,174
Operating loss			(42)	(42)
Purchase price				34,163
Cash acquired on acquisition				3,061
Accounts receivable, gross contractual amount			10,306	10,306
Accounts receivable expected to be uncollectible			106	106
Goodwill	32,247	25,809	6,601	6,601
Intangible Assets before Foreign Currency Adjustment			9,871	9,871
Increase in intangible assets, net, fluctuations in foreign currency exchange rates				362
Amortization expense			$ 649	$ 649