Restatement of Consolidated Financial Statements - Schedule of Impact of Restatement Adjustments on Consolidated Statement of Cash Flow (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities
Net loss	$ (21,605)	$ (17,589)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization	7,268	8,391
Provision for severance benefits	4,034	4,286
Bad debt expenses	94	(12)
Amortization of debt issuance costs and original issue discount	149	283
Loss on foreign currency translation, net	11,007	29,179
Restructuring and impairment charges		618
Stock-based compensation	617	490
Other	367	606
Changes in operating assets and liabilities
Accounts receivable	(28,094)	3,738
Inventories, net	(10,028)	(2,705)
Other receivables	691	(1,266)
Other current assets	(806)	3,529
Deferred tax assets	366	775
Accounts payable	(837)	2,136
Other accounts payable	(1,230)	10,412
Accrued expenses	(3,273)	(1,202)
Other current liabilities	(1,790)	(5,045)
Other non-current liabilities	548	334
Payment of severance benefits	(1,514)	(627)
Other	(150)	(48)
Net cash provided by operating activities	(44,186)	36,283
Cash flows from investing activities
Purchase of plant, property and equipment	(6,259)	(31,652)
Payment for intellectual property registration	(92)	(142)
Payment of guarantee deposits	(289)	(741)
Other	7	100
Net cash used in investing activities	(6,633)	(32,435)
Cash flows from financing activities
Proceeds from issuance of common stock	67	1,006
Acquisition of treasury stock		(6,000)
Net cash used in financing activities	67	(4,994)
Effect of exchange rates on cash and cash equivalents	1,914	1,895
Net increase in cash and cash equivalents	(48,838)	749
Cash and cash equivalents
Beginning of the period	153,606	182,238
End of the period	104,768	182,987
Supplemental cash flow information
Cash paid for interest	7,340	1
Cash paid for income taxes	(21)	6,204
Non-cash investing activities
Property, plant and equipment additions in other accounts payable	1,271	1,101
As Previously Reported [Member]
Cash flows from operating activities
Net loss		(7,405)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization		8,522
Provision for severance benefits		4,229
Bad debt expenses		30
Amortization of debt issuance costs and original issue discount		283
Loss on foreign currency translation, net		28,280
Restructuring and impairment charges		618
Stock-based compensation		420
Other		606
Changes in operating assets and liabilities
Accounts receivable		(6,409)
Inventories, net		2,022
Other receivables		(1,278)
Other current assets		2,014
Deferred tax assets		2,182
Accounts payable		2,290
Other accounts payable		9,734
Accrued expenses		(1,125)
Other current liabilities		(5,838)
Other non-current liabilities		(957)
Payment of severance benefits		(627)
Other		(47)
Net cash provided by operating activities		37,544
Cash flows from investing activities
Purchase of plant, property and equipment		(32,927)
Payment for intellectual property registration		(142)
Payment of guarantee deposits		(741)
Other		100
Net cash used in investing activities		(33,710)
Cash flows from financing activities
Proceeds from issuance of common stock		1,006
Acquisition of treasury stock		(6,000)
Net cash used in financing activities		(4,994)
Effect of exchange rates on cash and cash equivalents		1,909
Net increase in cash and cash equivalents		749
Cash and cash equivalents
Beginning of the period		182,238
End of the period		182,987
Supplemental cash flow information
Cash paid for interest		1
Cash paid for income taxes		6,384
Adjustments [Member]
Cash flows from operating activities
Net loss		(10,184)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization		(131)
Provision for severance benefits		57
Bad debt expenses		(42)
Loss on foreign currency translation, net		899
Stock-based compensation		70
Changes in operating assets and liabilities
Accounts receivable		10,147
Inventories, net		(4,727)
Other receivables		12
Other current assets		1,515
Deferred tax assets		(1,407)
Accounts payable		(154)
Other accounts payable		678
Accrued expenses		(77)
Other current liabilities		793
Other non-current liabilities		1,291
Other		(1)
Net cash provided by operating activities		(1,261)
Cash flows from investing activities
Purchase of plant, property and equipment		1,275
Net cash used in investing activities		1,275
Cash flows from financing activities
Effect of exchange rates on cash and cash equivalents		(14)
Supplemental cash flow information
Cash paid for income taxes		(180)
Non-cash investing activities
Property, plant and equipment additions in other accounts payable		$ 1,101