Restatement of Consolidated Financial Statements - Schedule of Impact of Restatement Adjustments on Previously Reported Consolidated Statement of Operations (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net sales	$ 164,164,000	$ 194,322,000
Cost of sales	123,887,000	136,087,000
Gross profit	40,277,000	58,235,000
Selling, general and administrative expenses	25,027,000	20,808,000
Research and development expenses	23,137,000	21,015,000
Restructuring and impairment charges		2,446,000
Operating income	(7,887,000)	13,966,000
Other income (expenses)
Interest expense, net	(4,070,000)	(5,849,000)
Foreign currency loss, net	(9,406,000)	(23,458,000)
Others	561,000	353,000
Net other income(expense)	(12,915,000)	(28,954,000)
Loss before income taxes	(20,802,000)	(14,988,000)
Income tax expenses	803,000	2,601,000
Net loss	(21,605,000)	(17,589,000)
Loss per common share-
Basic	$ (0.63)	$ (0.49)
Diluted	$ (0.63)	$ (0.49)
Weighted average number of shares-
Basic	34,052,875	35,539,413
Diluted	34,052,875	35,539,413
As Previously Reported [Member]
Net sales		205,298,000
Cost of sales		139,555,000
Gross profit		65,743,000
Selling, general and administrative expenses		19,791,000
Research and development expenses		20,582,000
Restructuring and impairment charges		2,446,000
Operating income		22,924,000
Other income (expenses)
Interest expense, net		(5,849,000)
Foreign currency loss, net		(22,558,000)
Others		(260,000)
Net other income(expense)		(28,667,000)
Loss before income taxes		(5,743,000)
Income tax expenses		1,662,000
Net loss		(7,405,000)
Loss per common share-
Basic		$ (0.21)
Diluted		$ (0.21)
Weighted average number of shares-
Basic		35,539,413
Diluted		35,539,413
Adjustments [Member]
Net sales		(10,976,000)
Cost of sales		(3,468,000)
Gross profit		(7,508,000)
Selling, general and administrative expenses		1,017,000
Research and development expenses		433,000
Operating income		(8,958,000)
Other income (expenses)
Foreign currency loss, net		(900,000)
Others		613,000
Net other income(expense)		(287,000)
Loss before income taxes		(9,245,000)
Income tax expenses		939,000
Net loss		(10,184,000)
Adjustments [Member] | Revenue Recognition [Member]
Net sales		(10,416,000)
Cost of sales		(8,647,000)
Gross profit		(1,769,000)
Selling, general and administrative expenses		(89,000)
Operating income		(1,680,000)
Other income (expenses)
Foreign currency loss, net		(907,000)
Others		53,000
Net other income(expense)		(854,000)
Loss before income taxes		(2,534,000)
Net loss		(2,534,000)
Adjustments [Member] | Inventory Reserves [Member]
Cost of sales		3,860,000
Gross profit		(3,860,000)
Operating income		(3,860,000)
Other income (expenses)
Loss before income taxes		(3,860,000)
Net loss		(3,860,000)
Adjustments [Member] | Understated Employee Benefits [Member]
Cost of sales		132,000
Gross profit		(132,000)
Selling, general and administrative expenses		19,000
Research and development expenses		51,000
Operating income		(202,000)
Other income (expenses)
Loss before income taxes		(202,000)
Net loss		(202,000)
Adjustments [Member] | Tax Matters [Member]
Selling, general and administrative expenses		180,000
Operating income		(180,000)
Other income (expenses)
Loss before income taxes		(180,000)
Income tax expenses		939,000
Net loss		(1,119,000)
Adjustments [Member] | Maintenance Costs [Member]
Cost of sales		2,432,000
Gross profit		(2,432,000)
Research and development expenses		55,000
Operating income		(2,487,000)
Other income (expenses)
Loss before income taxes		(2,487,000)
Net loss		(2,487,000)
Adjustments [Member] | Cost Center Allocation [Member]
Cost of sales		(844,000)
Gross profit		844,000
Selling, general and administrative expenses		860,000
Research and development expenses		(16,000)
Adjustments [Member] | Account Classification [Member]
Net sales		(560,000)
Cost of sales		(404,000)
Gross profit		(156,000)
Research and development expenses		404,000
Operating income		(560,000)
Other income (expenses)
Others		560,000
Net other income(expense)		560,000
Adjustments [Member] | Other Adjustments [Member]
Cost of sales		3,000
Gross profit		(3,000)
Selling, general and administrative expenses		47,000
Research and development expenses		(61,000)
Operating income		11,000
Other income (expenses)
Foreign currency loss, net		7,000
Net other income(expense)		7,000
Loss before income taxes		18,000
Net loss		$ 18,000