Magnachip Semiconductor (MX) 10-Q 12 Feb 15 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Jan. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q1
Trading Symbol	MX
Entity Registrant Name	MAGNACHIP SEMICONDUCTOR Corp
Entity Central Index Key	1325702
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		34,056,468

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets
Cash and cash equivalents	$104,768	$153,606
Restricted cash	4	4
Accounts receivable, net	105,679	78,898
Inventories, net	83,697	74,698
Other receivables	5,276	6,011
Prepaid expenses	12,835	9,194
Current deferred income tax assets	1,335	1,348
Other current assets	8,062	10,403
Total current assets	321,656	334,162
Property, plant and equipment, net	251,584	254,297
Intangible assets, net	2,745	3,111
Long-term prepaid expenses	14,829	16,405
Deferred income tax assets	611	896
Other non-current assets	16,618	16,319
Total assets	608,043	625,190
Current liabilities
Accounts payable	73,682	75,059
Other accounts payable	20,540	15,670
Accrued expenses	64,761	65,494
Other current liabilities	4,166	5,872
Total current liabilities	163,149	162,095
Long-term borrowings, net	223,951	223,923
Accrued severance benefits, net	135,013	134,172
Other non-current liabilities	20,213	23,459
Total liabilities	542,326	543,649
Commitments and Contingencies (Note 17)
Stockholders' equity
Common stock, $0.01 par value, 150,000,000 shares authorized, 40,635,128 shares issued and 34,056,363 outstanding at March 31, 2014 and 40,627,131 shares issued and 34,048,366 outstanding at December 31, 2013	406	406
Additional paid-in capital	116,906	116,222
Retained earnings	84,284	105,889
Treasury stock, 6,578,765 shares at March 31, 2014 and December 31, 2013	-90,918	-90,918
Accumulated other comprehensive loss	-44,961	-50,058
Total stockholders' equity	65,717	81,541
Total liabilities and stockholders' equity	$608,043	$625,190

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	40,635,128	40,627,131
Common stock, shares outstanding	34,056,363	34,048,366
Treasury stock, shares	6,578,765	6,578,765

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Net sales	$164,164	$194,322
Cost of sales	123,887	136,087
Gross profit	40,277	58,235
Selling, general and administrative expenses	25,027	20,808
Research and development expenses	23,137	21,015
Restructuring and impairment charges		2,446
Operating income (loss)	-7,887	13,966
Other expenses
Interest expense, net	-4,070	-5,849
Foreign currency loss, net	-9,406	-23,458
Other	561	353
Net other income (expenses)	-12,915	-28,954
Loss before income taxes	-20,802	-14,988
Income tax expenses	803	2,601
Net loss	($21,605)	($17,589)
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

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss	($21,605)	($17,589)
Other comprehensive income
Foreign currency translation adjustments	6,619	13,733
Derivative adjustments
Fair valuation of derivatives	-1,801	-5,482
Reclassification adjustment for loss (gain) on derivatives included in net loss	3	-250
Unrealized gain on investments	276	320
Total comprehensive loss	($16,508)	($9,268)

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]
In Thousands, except Share data
Balance, beginning at Dec. 31, 2012	$191,529	$396	$102,409	$170,092	($39,918)	($41,450)
Balance, Shares beginning at Dec. 31, 2012		35,635,357
Stock-based compensation	490		490
Exercise of stock options	994	1	993
Exercise of stock options, Shares		147,810
Exercise of warrants	12		12
Exercise of warrants, Shares		749
Acquisition of treasury stock	-6,000				-6,000
Acquisition of treasury stock, Shares		-375,884
Other comprehensive income, net	8,321					8,321
Net loss	-17,589			-17,589
Balance, ending at Mar. 31, 2013	177,757	397	103,904	152,503	-45,918	-33,129
Balance, Shares ending at Mar. 31, 2013		35,408,032
Balance, beginning at Dec. 31, 2013	81,541	406	116,222	105,889	-90,918	-50,058
Balance, Shares beginning at Dec. 31, 2013	34,048,366	34,048,366
Stock-based compensation	617		617
Exercise of stock options	48		48
Exercise of stock options, Shares		6,795
Exercise of warrants	19		19
Exercise of warrants, Shares		1,202
Other comprehensive income, net	5,097					5,097
Net loss	-21,605			-21,605
Balance, ending at Mar. 31, 2014	$65,717	$406	$116,906	$84,284	($90,918)	($44,961)
Balance, Shares ending at Mar. 31, 2014	34,056,363	34,056,363

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	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 (used in) 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 (used in) 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 provided by (used in) financing activities	67	-4,994
Effect of exchange rates on cash and cash equivalents	1,914	1,895
Net increase (decrease) 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 (refunded) for income taxes	-21	6,204
Non-cash investing activities
Property, plant and equipment additions in other accounts payable	$1,271	$1,101

Business_Basis_of_Presentation

Business, Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]
Business, Basis of Presentation and Significant Accounting Policies	1. Business, Basis of Presentation and Significant Accounting Policies
	Business
	MagnaChip Semiconductor Corporation (together with its subsidiaries, the “Company”) is a Korea-based designer and manufacturer of analog and mixed-signal semiconductor products for high-volume consumer, computer and communication applications. The Company’s business is comprised of three key business lines: Display Solutions, Power Solutions and Semiconductor Manufacturing Services. The Company’s Display Solutions products include display drivers for use in a wide range of flat panel displays and mobile multimedia devices. The Company’s Power Solutions products include discrete and integrated circuit solutions for power management in high-volume consumer, computer, communication and industrial applications. The Company’s Semiconductor Manufacturing Services provide specialty analog and mixed-signal foundry services for fabless semiconductor companies that serve the consumer, computing and wireless end markets.
	Basis of Presentation
	The accompanying unaudited interim consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“US GAAP”). These interim consolidated financial statements include normal recurring adjustments and the elimination of all intercompany accounts and transactions which are, in the opinion of management, necessary to provide a fair statement of the Company’s financial condition and results of operations for the periods presented. These interim consolidated financial statements are presented in accordance with ASC 270, “Interim Reporting” (“ASC 270”) and, accordingly, do not include all of the information and note disclosures required by US GAAP for complete financial statements. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the results to be expected for a full year or for any other periods.
	The December 31, 2013 balance sheet data was derived from the Company’s audited financial statements, but does not include all disclosures required by US GAAP.
	Recent Accounting Pronouncements
	In August 2014, the FASB issued Accounting Standards Update No. 2014-15, “Presentation of Financial Statements — Going Concern” (“ASU 2014-15”), which provides guidance on determining when and how to disclose going-concern uncertainties in the financial statements. ASU 2014-15 requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued. An entity will be required to provide certain disclosures if conditions of events raise substantial doubt about the entity’s ability to continue as a going concern. ASU 2014-15 is effective for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2014-15 on its consolidated financial statements.
	In June 2014, the FASB issued Accounting Standards Update No. 2014-11, “Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures” (“ASU 2014-11”). The guidance in this update changes the accounting for repurchase-to-maturity transactions and repurchasing financing arrangements. It also requires enhanced disclosures about repurchase agreements and other similar transactions. The accounting changes in this update are effective for public companies for the first interim or annual period beginning after December 15, 2014. In addition, for public companies, the disclosure for certain transactions accounted for as a sale is effective for the first interim or annual period beginning on or after December 15, 2014, and the disclosure for transactions accounted for as secured borrowings is required to be presented for annual periods beginning after December 15, 2014, and interim periods beginning after March 15, 2015. Early application is not permitted. The Company is currently evaluating the impact of the adoption of ASU 2014-11 on its consolidated financial statements.
	In May 2014, the FASB issued Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”). ASU 2014-09 supersedes the revenue recognition requirements in “Revenue Recognition (Topic 605)”, and requires entities to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is not permitted. The Company is currently evaluating the impact of the adoption of ASU 2014-09 on its consolidated financial statements.

Restatement_of_Consolidated_Fi

Restatement of Consolidated Financial Statements	3 Months Ended
	Mar. 31, 2014
Accounting Changes and Error Corrections [Abstract]
Restatement of Consolidated Financial Statements	2. Restatement of Consolidated Financial Statements
	These interim financial statements should be read in conjunction with the consolidated financial statements for the year ended December 31, 2013 contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2013 (the “2013 Form 10-K”), which was filed on February 12, 2015.
	Background and Scope of Investigation
	In January 2014, the Audit Committee of the Company’s Board of Directors (the “Audit Committee”) commenced an internal investigation into the Company’s accounting practices and procedures with outside professional advisors (the “Independent Investigation”). The Independent Investigation involved procedures that included forensic analysis and inquiry directed to aspects of the Company’s accounting and financial reporting practices, and evaluated aspects of its historical accounting and financial reporting practices since 2011. The Independent Investigation initially raised questions relating to numerous accounting transactions, most of which involved revenue recognition practices relating to distributor relationships.
	Based on initial findings and observations from the Independent Investigation regarding errors in the Company’s revenue recognition practices related to sales through distributors, the Company announced on March 11, 2014 that the Audit Committee concluded that the Company’s previously issued financial statements for each of the years ended December 31, 2012 and December 31, 2011 and the quarters ended March 31, June 30 and September 30 in 2013 and 2012 should no longer be relied upon.
	The Independent Investigation continued through October 2014 and identified numerous accounting errors, most of which involved revenue recognition, cost of goods sold, inventory reserves, fixed asset capitalization, and expense recognition and allocation. It also identified deficiencies regarding business practices related to distributors, non-distributor customers and vendors. Concurrently with the Independent Investigation, management conducted extensive internal review of its financial accounting and reporting practices and internal control over financial reporting. The Independent Investigation and management’s internal review identified evidence of errors in the Company’s accounting and deficiencies in its internal control over financial reporting.
	Restatement Adjustments
	As a result of the issues identified in the Independent Investigation and management’s internal review, the Company restated its previously reported consolidated financial statements for the three months ended March 31, 2013 in order to correct certain previously reported amounts.
	The impact of the errors to the previous statement of operations, statement of cash flows and statement of comprehensive income has been detailed in the tables below. A description of the nature of the errors follows.
	Revenue Recognition
	Sales through Distributors — The largest portion of revenue recognition adjustments relate to correcting the timing and amount of revenue recognized on the sale of products through certain distributors. During the course of the Independent Investigation and management’s internal review, it was determined that the application of its revenue recognition policy was not appropriate in these situations. Revenue had been recognized without persuasive evidence of an arrangement and the collectability of the sales price not being reasonably assured. Furthermore, in some circumstances, revenue was recognized prior to risk of loss being transferred.
	Accordingly, related revenues and cost of sales were reversed in the period in which the accounting errors took place and recognized in subsequent periods when all of the revenue recognition criteria were met. These adjustments also include the impact of foreign currency exchange rate differences between periods of de-recognition and recognition of the revenue transactions.
	Other — The other revenue recognition adjustments include transactions where the Company recognized revenue in an incorrect period or recognized an incorrect amount of revenue. The primary categories of other revenue recognition adjustments include the following:
		•		Cut-off — The Company identified certain sales transactions that were recognized prior to the transfer of inventory risk and title.
		•		Non-recurring Engineering (“NRE”) — The Company provides NRE services to develop prototype wafers mainly for the Company’s foundry service customers. The Company identified revenue related to certain NRE arrangements recognized earlier or later than at the time that the required prototype wafer was delivered.
		•		Concessions — The Company identified various types of unrecorded concessions provided to its distributors and customers, including future discounts, price adjustments, return rights, free products and others to incentivize distributors and customers to make purchases. Such concessions should be recorded as a deduction from revenues at the time when the related revenues are recognized.
		•		Direct Customer Sales — The Company identified certain sales transactions to a customer that were recognized when the products were taken from the Company’s manufacturing facility to its warehouse, rather than when the products were delivered to the customer’s location. The arrangement related to these transactions did not have a fixed schedule for delivery to a customer’s location and were prematurely recognized as revenues.
	Hedge Accounting — As a result of incorrect recognition of revenue discussed in Revenue Recognition – Sales through Distributors and Revenue Recognition – Other, the Company’s hedge accounting, related to the change in the effective portion of our derivative instrument’s gains and losses, was adjusted as key assumptions determining the amount are derived from revenues.
	Reserves — As a result of incorrect recognition of revenue discussed in Revenue Recognition – Sales through Distributors and Revenue Recognition – Other, adjustments for reserves, related to estimated refunds, low yield compensation, and warranty liabilities, also required corrections as key assumptions in determining these amounts are derived from revenues.
	Manufacturing Cost —The Company corrected certain fabrication and back-end processing costs that were not recorded consistently with the progression of its manufacturing activities. As a result, the Company’s cost of sales was decreased by approximately $1,400 thousand for the three months ended March 31, 2013, to account for manufacturing costs during the period in which they were incurred.
	Inventory Reserves
	The Company corrected errors with respect to how the Company previously forecasted revenues for the purposes of determining inventory reserves. As a result, the Company performed a retrospective review of its inventory reserve calculation and revised the revenue forecast component of the reserve calculation. In addition, as a result of the correction of revenue for certain transactions discussed in Revenue Recognition – Sales through Distributors and Revenue Recognition – Other, a significant portion of the revenues were reversed rather than deferred. The failure of the anticipated orders from final customers materializing resulted in a significantly higher excess and obsolete reserves for the restatement and subsequent periods. In addition, the Company corrected errors with respect to obsolete and aged inventory reserves that were previously understated due to the misclassification or errors in certain inventory items.
	Understated Employee Benefits
	The Company identified that certain amounts of earned vacation that were not included in calculating its severance accrual, resulting in an understatement of accrued severance benefits.
	The Company also identified that vested compensation claims by employees who have rendered long-term services were accounted for on a cash basis rather than on an accrual basis, resulting in an understatement of long-term service liabilities.
	Settlement Obligations
	The Company identified certain cash and in-kind payments to a customer in connection with settling a claim involving the Company’s product that may have caused a failure in the customer’s product. Although the Company does not agree with the claim, as its product met the customers’ specifications, the Company considered a number of factors and decided not to dispute the claim but make certain cash and/or in-kind payments as demanded by the customer. A number of cash and in-kind payments were made to the customer since 2011 and were recorded as cost of sales and/or reduction of revenues at the time that they were paid rather than accrued when each cash or in-kind payment became probable.
	Tax Matters
	Income Tax — Realization of the deferred tax assets is dependent on the Company’s ability to generate future taxable income. In the previously reported consolidated financial statements for the year ended December 31, 2012, the Company had released $64,749 thousand of valuation allowance against deferred tax assets at the Company’s Korean subsidiary and, consequently, a corresponding amount of income tax benefit was recognized.
	During the management’s internal review, key assumptions and forecast of future taxable income were reassessed based on restated financial data as to whether deferred tax assets will ultimately be realized. In its reassessment, the Company concluded that the objective and verifiable negative evidence represented by recent actual operating losses outweighed more subjective positive evidence of anticipated future income over the periods in which the deferred tax assets are deductible. As a result, the Company determined that it was necessary to record a full valuation allowance on deferred tax assets of $64,749 thousand as of December 31, 2012 and for each subsequent quarter thereafter. The related expense was recorded in the Company’s statement of operations for the year ended December 31, 2012 as an income tax expense. In addition, the management’s review identified income tax adjustments attributable to certain foreign subsidiaries other than Korea and made an adjustment amounting to $112 thousand.
	The restatement adjustments for the three months ended March 31, 2013 impacted our temporary differences between our book income and taxable income, which resulted in an increase of our deferred tax assets for which a full valuation allowance was recorded for the fiscal period then ended and thus there was no tax impact of the other restatement adjustments.
	Other — The Company identified liabilities related to non-income-based taxes that the Company may be exposed to in connection with certain tax positions taken. We considered the period in which the underlying cause of action occurred, degree of probability of an unfavorable outcome and whether we could make a reasonable estimate.
	Maintenance Costs
	The Company identified certain maintenance expenses that were inappropriately capitalized and depreciated. As a result, the Company corrected these errors by reversing the related amounts in property, plant and equipment, and recorded them in cost of sales and research and development expense. In addition, the Company identified certain cash payments to a maintenance supplies vendor, that (i) the vendor used to purchase products from distributors; (ii) the distributors then paid to the Company for those products; and (iii) in turn were applied to the Company’s aged accounts receivable.
	Account Classification
	Revenue — The Company corrected the classification of rental income that was previously recorded as net sales when it should have been recorded in other income (expenses).
	Expense — The Company identified errors in classification of expenses that were recorded as cost of sales when they should have been recorded as research and development for the three months ended March 31, 2013.
	Cost Center Allocation
	The Company identified costs from certain cost centers that were not always allocated consistently with the nature of the Company’s business. As a result, the Company recorded adjustments to reclassify the related costs from cost of sales to selling, general and administrative expenses.
	Other Adjustments
	In addition to the restatement adjustments described above, the Company has identified other errors that are not material, individually or in the aggregate, but have been recorded in connection with the restatement.
	Included in other adjustments are as follows:
		•		Accrued Liabilities — The Company identified costs related to certain goods and services that were recorded at the time of receipt of invoice rather than when the goods were delivered or services were rendered. As a result, the Company recorded adjustments to cost of sales and research and development expense.
		•		Stock-based Compensation — The Company identified incorrect application of assumptions in computation of stock-based compensation expenses. As a result, the Company recorded adjustments to increase compensation expenses.
	The following table presents the impact of the restatement adjustments on the Company’s previously reported consolidated statement of operations for the three months ended March 31, 2013:
						Three Months Ended March 31, 2013
						Restatement Adjustments
			As Previously			Revenue			Inventory			Understated			Settlement		Tax			Maintenance			Cost			Account			Other			Total			As
			Reported			Recognition			Reserves			Employee			Obligations		Matters			Cost			Center			Classification			Adjustments			Adjustments			Restated
												Benefits											Allocation
	Net sales		$	205,298		$	(10,416	)	$	—		$	—		$	—	$	—		$	—		$	—		$	(560	)	$	—		$	(10,976	)	$	194,322
	Cost of sales			139,555			(8,647	)		3,860			132			—		—			2,432			(844	)		(404	)		3			(3,468	)		136,087
	Gross profit			65,743			(1,769	)		(3,860	)		(132	)		—		—			(2,432	)		844			(156	)		(3	)		(7,508	)		58,235
	Selling, general and administrative expenses			19,791			(89	)		—			19			—		180			—			860			—			47			1,017			20,808
	Research and development expenses			20,582			—			—			51			—		—			55			(16	)		404			(61	)		433			21,015
	Restructuring and impairment charges			2,446			—			—			—			—		—			—			—			—			—			—			2,446
	Operating income			22,924			(1,680	)		(3,860	)		(202	)		—		(180	)		(2,487	)		—			(560	)		11			(8,958	)		13,966
	Other income (expenses)
	Interest expense, net			(5,849	)		—			—			—			—		—			—			—			—			—			—			(5,849	)
	Foreign currency loss, net			(22,558	)		(907	)		—			—			—		—			—			—			—			7			(900	)		(23,458	)
	Others			(260	)		53			—			—			—		—			—			—			560			—			613			353
				(28,667	)		(854	)		—			—			—		—			—			—			560			7			(287	)		(28,954	)
	Loss before income taxes			(5,743	)		(2,534	)		(3,860	)		(202	)		—		(180	)		(2,487	)		—			—			18			(9,245	)		(14,988	)
	Income tax expenses			1,662			—			—			—			—		939			—			—			—			—			939			2,601
Net loss		$	(7,405	)	$	(2,534	)	$	(3,860	)	$	(202	)	$	—	$	(1,119	)	$	(2,487	)	$	—		$	—		$	18		$	(10,184	)	$	(17,589	)
Loss per common share—
Basic		$	(0.21	)																														$	(0.49	)
Diluted		$	(0.21	)																														$	(0.49	)
Weighted average number of shares—
Basic			35,539,413																																35,539,413
Diluted			35,539,413																																35,539,413
Note— Settlement Obligations column presented in the table above does not impact the statement operations for the three months ended March 2013.
Statement of Cash Flows
The following table presents the impact of the restatement adjustments on the Company’s consolidated statement of cash flow for three months ended March 31, 2013:
Three Months Ended March 31, 2013
		As Previously			Restatement			As
		Reported			Adjustments			Restated
Cash flows from operating activities
Net loss		$	(7,405	)	$	(10,184	)	$	(17,589	)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization			8,522			(131	)		8,391
Provision for severance benefits			4,229			57			4,286
Bad debt expenses			30			(42	)		(12	)
Amortization of debt issuance costs and original issue discount			283			—			283
Loss on foreign currency translation, net			28,280			899			29,179
Restructuring and impairment charges			618			—			618
Stock-based compensation			420			70			490
Other			606			—			606
Changes in operating assets and liabilities
Accounts receivable			(6,409	)		10,147			3,738
Inventories, net			2,022			(4,727	)		(2,705	)
Other receivables			(1,278	)		12			(1,266	)
Other current assets			2,014			1,515			3,529
Deferred tax assets			2,182			(1,407	)		775
Accounts payable			2,290			(154	)		2,136
Other accounts payable			9,734			678			10,412
Accrued expenses			(1,125	)		(77	)		(1,202	)
Other current liabilities			(5,838	)		793			(5,045	)
Other non-current liabilities			(957	)		1,291			334
Payment of severance benefits			(627	)		—			(627	)
Other			(47	)		(1	)		(48	)
Net cash provided by operating activities			37,544			(1,261	)		36,283
Cash flows from investing activities
Purchase of plant, property and equipment			(32,927	)		1,275			(31,652	)
Payment for intellectual property registration			(142	)		—			(142	)
Payment of guarantee deposits			(741	)		—			(741	)
Other			100			—			100
Net cash used in investing activities			(33,710	)		1,275			(32,435	)
Cash flows from financing activities
Proceeds from issuance of common stock			1,006			—			1,006
Acquisition of treasury stock			(6,000	)		—			(6,000	)
Net cash used in financing activities			(4,994	)		—			(4,994	)
Effect of exchange rates on cash and cash equivalents			1,909			(14	)		1,895
Net increase in cash and cash equivalents			749			—			749
Cash and cash equivalents
Beginning of the period			182,238			—			182,238
End of the period		$	182,987		$	—		$	182,987
Supplemental cash flow information
Cash paid for interest		$	1		$	—		$	1
Cash paid for income taxes		$	6,384		$	(180	)	$	6,204
Non-cash investing activities
Property, plant and equipment additions in other accounts payable		$	—		$	1,101		$	1,101
Comprehensive Income
The following table presents the impact of the restatement adjustments on the Company’s previously reported consolidated statements of comprehensive income for the three months ended March 31, 2013:
		Three Months Ended
		March 31, 2013
		As Previously			As Restated
		Reported
Net loss		$	(7,405	)	$	(17,589	)
Other comprehensive income :
Foreign currency translation adjustments			9,133			13,733
Derivative adjustments
Fair valuation of derivatives			(4,207	)		(5,482	)
Reclassification adjustment for gain on derivatives included in net loss			(304	)		(250	)
Unrealized gain on investments			228			320
Total comprehensive loss		$	(2,555	)	$	(9,268	)

Sales_of_Accounts_Receivable_a

Sales of Accounts Receivable and Receivable Discount Program	3 Months Ended
	Mar. 31, 2014
Receivables [Abstract]
Sales of Accounts Receivable and Receivable Discount Program	3. Sales of Accounts Receivable and Receivable Discount Program
	The Company has entered into an agreement to sell selected trade accounts receivable to a financial institution from time to time since March 2012. After the sale, the Company does not retain any interest in the receivables and the applicable financial institution collects these accounts receivable directly from the customer. The proceeds from the sales of these accounts receivable totaled $3,139 thousand and $10,072 thousand for the three months ended March 31, 2014 and 2013, respectively, and these sales resulted in pre-tax losses of $8 thousand and $20 thousand for the three months ended March 31, 2014 and 2013, respectively, which are included in selling, general and administrative expenses in the consolidated statements of operations. Net proceeds of this accounts receivable sale program are recognized in the consolidated statements of cash flows as part of operating cash flows.
	The Company uses receivable discount programs with certain customers. These discount arrangements allows the Company to accelerate collection of customers’ receivables. While these arrangements have reduced the Company’s working capital needs, there can be no assurance that these programs will continue in the future.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]
Inventories	4. Inventories
	Inventories as of March 31, 2014 and December 31, 2013 consist of the following:
		March 31,			December 31,
		2014			2013
	Finished goods	$	48,596		$	43,734
	Semi-finished goods and work-in-process		94,061			92,030
	Raw materials		10,555			9,464
	Materials in-transit and other		750			1,870
	Less: inventory reserve		(70,265	)		(72,400	)
	Inventories, net	$	83,697		$	74,698
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Beginning balance	$	(72,400	)	$	(25,429	)
	Change in reserve		(2,788	)		(7,777	)
	Write off		4,012			417
	Translation adjustments		911			1,125
	Ending balance	$	(70,265	)	$	(31,664	)
	Inventory reserve represents the Company’s best estimate in value lost due to excessive inventory level, physical deterioration, obsolescence, changes in price levels, or other causes based on individual facts and circumstances. Inventory reserve relates to inventory items including finished goods, semi-finished goods and work-in-process. Write off of this reserve is recognized only when the related inventory has been disposed or scrapped.

Property_Plant_and_Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	5. Property, Plant and Equipment
	Property, plant and equipment as of March 31, 2014 and December 31, 2013 comprise the following:
		March 31,			December 31,
		2014			2013
	Buildings and related structures	$	80,145		$	81,050
	Machinery and equipment		272,443			269,840
	Vehicles and others		23,333			22,397
			375,921			373,287
	Less: accumulated depreciation		(141,525	)		(136,397	)
	Land		17,188			17,407
	Property, plant and equipment, net	$	251,584		$	254,297

Intangible_Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	6. Intangible Assets
	Intangible assets as of March 31, 2014 and December 31, 2013 are as follows:
		March 31,			December 31,
		2014			2013
	Technology	$	19,827		$	20,081
	Customer relationships		29,072			29,444
	Intellectual property assets		7,827			7,829
	Less: accumulated amortization		(53,981	)		(54,243	)
	Intangible assets, net	$	2,745		$	3,111

Accrued_Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2014
Payables and Accruals [Abstract]
Accrued Expenses	7. Accrued Expenses
	Accrued expenses as of March 31, 2014 and December 31, 2013 are as follows:
		March 31,		December 31,
		2014		2013
	Payroll, benefits and related taxes,              excluding severance benefits	$	21,323	$	19,869
	Withholding tax levied on intercompany interest income		24,792		23,872
	Interest on senior notes		3,105		6,749
	Settlement obligations		4,677		6,460
	Outside service fees		3,457		1,462
	Others		7,407		7,082
	Accrued expenses	$	64,761	$	65,494
	Settlement obligations
	Settlement obligations related to settling claims involving the Company’s products are accrued when they are deemed probable and can be reasonably estimated. As of March 31, 2014, the settlement obligation of $6,037 thousand is included in other non-current liabilities in the consolidated balance sheet.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	8. Derivative Financial Instruments
	The Company’s Korean subsidiary, MagnaChip Semiconductor, Ltd., entered into zero cost collar contracts to hedge the risk of changes in the functional-currency-equivalent cash flows attributable to currency rate changes on U.S. dollar denominated revenues.
	Details of derivative contracts as of March 31, 2014 are as follows:
	Date of transaction	Type of derivative		Total notional amount				Month of settlement
	8-Mar-13	Zero cost collar		$	54,000			April to June 2014
	April 5, 2013	Zero cost collar		$	54,000			July to September 2014
	May 29, 2013	Zero cost collar		$	54,000			October to December 2014
	March 12, 2014	Zero cost collar		$	54,000			January to March 2015
	The zero cost collar contracts qualify as cash flow hedges under ASC 815, “Derivatives and Hedging,” (“ASC 815”), since at both the inception of the contracts and on an ongoing basis, the hedging relationship was and is expected to be highly effective in achieving offsetting cash flows attributable to the hedged risk during the term of the contracts. The Company is utilizing the “hypothetical derivative” method to measure the effectiveness by comparing the changes in value of the actual derivative versus the change in fair value of the “hypothetical derivative.”
	The fair values of the Company’s outstanding zero cost collar contracts recorded as assets as of March 31, 2014 and December 31, 2013 are as follows:
	Derivatives designated as hedging instruments:			March 31,				December 31,
				2014				2013
	Asset Derivatives:
	Zero cost collars	Other current assets		$	3,191			$	4,912
	Liabilities Derivatives:
	Zero cost collars	Other current liabilities		$	169			$	—
	Offsetting of derivative assets as of March 31, 2014 and December 31, 2013 is as follows:
	As of March 31, 2014	Gross amounts of				Gross amounts				Net amounts of				Gross amounts not offset							Net amount
		recognized				offset in the				assets/liabilities				in the balance sheets
		assets/liabilities				balance sheets				presented in the
										balance sheets				Financial				Cash collateral
														instruments				received/
																		pledged
	Asset Derivatives:
	Zero cost collars	$	3,191			$	—			$	3,191			$	(169	)		$	—		$	3,022
	Liability Derivatives:
	Zero cost collars	$	169			$	—			$	169			$	(169	)		$	—		$	—
	As of December 31, 2013	Gross amounts of				Gross amounts				Net amounts of				Gross amounts not offset							Net amount
		recognized				offset in the				assets/liabilities				in the balance sheets
		assets/liabilities				balance sheets				presented in the
										balance sheets				Financial				Cash collateral
														instruments				received/
																		pledged
	Asset Derivatives:
	Zero cost collars	$	4,912			$	—			$	4,912			$	—			$	—		$	4,912
	For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of accumulated other comprehensive income (“AOCI”) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative, representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness, are recognized in current earnings.
	The following table summarizes the impact of derivative instruments on the consolidated statement of operations for the three months ended March 31, 2014 and 2013:
	Derivatives in ASC	Amount of Gain (Loss)								Location of		Amount of Gain (Loss)								Location of	Amount of Gain
	815 Cash Flow Hedging	Recognized in								Gain (Loss)		Reclassified from								Gain (Loss)	(Loss)
	Relationships	AOCI on								Reclassified from		AOCI into								Recognized in	Recognized in
		Derivatives								AOCI into		Statement of								Statement of	Statement of
		(Effective Portion)								Statement of		Operations								Operations on	Operations on
										Operations		(Effective Portion)								Derivative	Derivatives
										(Effective Portion)										(Ineffective	(Ineffective Portion
																				Portion and	and Amount
																				Amount	Excluded from
																				Excluded from	Effectiveness Testing)
																				Effectiveness
																				Testing)
		Three Months Ended										Three Months Ended									Three Months Ended
		March 31,										March 31,									March 31,
		2014				2013						2014				2013					2014			2013
						(As Restated)										(As Restated)								(As Restated)
	Zero cost collars	$	(1,801	)		$	(5,482	)		Net sales		$	(3	)		$	250			Other income	$	(16	)	$	(214	)
																				(expenses) —Others
	Total	$	(1,801	)		$	(5,482	)				$	(3	)		$	250				$	(16	)	$	(214	)
	As of March 31, 2014, the amount expected to be reclassified from accumulated other comprehensive income into earnings within the next twelve months is $2,912 thousand.
	The Company’s zero cost collar contracts are subject to termination upon the occurrence of the following events:
	(i) On the last day of a fiscal quarter, the sum of qualified and unrestricted cash and cash equivalents held by the Company is less than $30 million.
	(ii) The rating of the Company’s debt is B- or lower by Standard & Poor’s Ratings Group or any successor rating agency thereof (“S&P”) or B3 or lower by Moody’s Investor Services, Inc. or any successor rating agency thereof (“Moody’s”) or the Company’s debt ceases to be assigned a rating by either S&P or Moody’s. See “Note 18. Subsequent Events” – Early termination of derivative contracts.
	In addition, the Company is required to deposit cash collateral with three financial institutions, the counterparties to the zero cost collar contracts, for any exposure in excess of $5 million for each financial institution. No cash collateral was required as of March 31, 2014.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. Fair Value Measurements
	The Company’s financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2014, and the basis for that measurement is as follows:
		Carrying Value		Fair Value		Quoted Prices in		Significant		Significant
				Measurement		Active Markets		Other		Unobservable
						for		Observable		Inputs
						Identical Asset		Inputs		(Level 3)
						(Level 1)		(Level 2)
	Assets:
	Available-for-sale securities	$	1,497	$	1,497	$	1,497	$	—	$	—
	Derivative assets (other current assets)		3,191		3,191		—		3,191		—
	Liabilities:
	Derivative liabilities (other current liabilities)		169		169		—		169		—
	As of March 31, 2014, the total carrying value and estimated fair value of the Company’s 6.625% Senior Notes due 2021 (the “2021 Notes”), which are not measured at fair value on a recurring basis, were $223,951 thousand and $225,563 thousand, respectively. The estimated fair value is based on Level 2 inputs.

LongTerm_Borrowings

Long-Term Borrowings	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]
Long-Term Borrowings	10. Long-Term Borrowings
	Long-term borrowings as of March 31, 2014 and December 31, 2013 are as follows:
		March 31,			December 31,
		2014			2013
	6.625% senior notes due July 2021	$	225,000		$	225,000
	Discount on senior notes		(1,049	)		(1,077	)
	Long-term borrowings, net of unamortized discount	$	223,951		$	223,923
	On July 18, 2013, the Company issued $225,000,000 aggregate principal amount of the 2021 Notes at a price of 99.5%. Interest on the 2021 Notes accrues at a rate of 6.625% per annum, payable semi-annually on January 15 and July 15 of each year, beginning on January 15, 2014.
	The Company used net proceeds from the issuance of the 2021 Notes of $218.8 million, which represents $225.0 million of principal amount net of $1.1 million of original issue discount and $5.1 million of debt issuance costs, together with cash on hand, to repay all of the Company’s 10.500% senior notes due April 2018, including applicable premium and accrued interest, and to pay related fees and expenses of the 2021 Notes offering.
	In connection with the refinancing of the Company’s senior notes, the Company recognized $32.8 million of loss on early extinguishment of senior notes, which consisted of $23.8 million from the applicable premium, $5.3 million from write-off of debt issuance costs, $1.9 million from write-off of discounts and $1.8 million of interest incurred during the notice period.
	The Company can optionally redeem all or a part of the 2021 Notes according to the following schedule: (i) at any time prior to July 15, 2016, the Company may on any one or more occasions redeem up to 35% of the aggregate principal amount of 2021 Notes issued under the Indenture, dated as of July 18, 2013, as supplemented by that certain First Supplemental Indenture, dated as of March 27, 2014 (collectively, the “Indenture”) at a redemption price equal to 106.625% of the principal amount of the 2021 Notes redeemed, plus accrued and unpaid interest and special interest, if any, to the date of redemption with the net proceeds of a qualified equity offering; (ii) at any time prior to July 15, 2017, the Company may on any one or more occasions redeem all or a part of the 2021 Notes at a redemption price equal to 100% of the principal amount of the notes redeemed, plus the applicable premium as of, and accrued and unpaid interest and special interest, if any, to the date of redemption; and (iii) on or after July 15, 2017, the Company may on any one or more occasions redeem all or a part of the 2021 Notes, at a redemption price equal to 103.313%, 101.656% and 100% of the principal amount of the notes redeemed in 2017, 2018 and 2019 and thereafter, respectively, plus accrued and unpaid interest and special interest, if any, on the notes redeemed, to the applicable date of redemption.
	The Indenture contains covenants that limit ability of the Company and its restricted subsidiaries to: (i) declare or pay any dividend or make any payment or distribution on account of or purchase or redeem the Company’s capital stock or equity interests of the restricted subsidiaries; (ii) make any principal payment on, or redeem or repurchase, prior to any scheduled repayment or maturity, any subordinated indebtedness; (iii) make certain investments; (iv) incur additional indebtedness and issue certain types of capital stock; (v) create or incur any lien (except for permitted liens) that secures obligations under any indebtedness; (vi) merge with or into or sell all or substantially all of the Company’s assets to other companies; (vii) enter into certain types of transactions with affiliates; (viii) guarantee the payment of any indebtedness; (ix) enter into sale-leaseback transactions; (x) enter into agreements that would restrict the ability of the restricted subsidiaries to make distributions with respect to their equity to the Company or other restricted subsidiaries, to make loans to the Company or other restricted subsidiaries or to transfer assets to the Company or other restricted subsidiaries; and (xi) designate unrestricted subsidiaries.
	These covenants will be subject to a number of exceptions and qualifications. Certain of these restrictive covenants will terminate if the notes are rated investment grade at any time.
	In connection with the issuance of the 2021 Notes, the Company capitalized certain costs and fees, which are being amortized using the effective interest method over its respective term, 2013 to 2021. Amortization costs, which were included in interest expense in the accompanying statements of operations, amounted to $123 thousand for the three months ended March 31, 2014. The remaining capitalized costs as of March 31, 2014, which were included in other non-current assets in the consolidated balance sheet, were $4,700 thousand.

Accrued_Severance_Benefits

Accrued Severance Benefits	3 Months Ended
	Mar. 31, 2014
Postemployment Benefits [Abstract]
Accrued Severance Benefits	11. Accrued Severance Benefits
	The majority of accrued severance benefits is for employees in the Company’s Korean subsidiary, MagnaChip Semiconductor Ltd. Pursuant to the Employee Retirement Benefit Security Act of Korea, eligible employees and executive officers with one or more years of service are entitled to severance benefits upon the termination of their employment based on their length of service and rate of pay. As of March 31, 2014, 98% of employees of the Company were eligible for severance benefits.
	Changes in accrued severance benefits are as follows:
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Beginning balance	$	135,356		$	116,036
	Provisions		4,034			4,286
	Severance payments		(1,514	)		(627	)
	Translation adjustments		(1,700	)		(4,377	)
			136,176			115,318
	Less: Cumulative contributions to the National Pension Fund		(375	)		(379	)
	Group severance insurance plan		(788	)		(754	)
	Accrued severance benefits, net	$	135,013		$	114,185
	The severance benefits funded through the Company’s National Pension Fund and group severance insurance plan will be used exclusively for payment of severance benefits to eligible employees. These amounts have been deducted from the accrued severance benefit balance.
	The Company is liable to pay the following future benefits to its non-executive employees upon their normal retirement age:
		Severance benefit
	Remainder of 2014	$	374
	2015		390
	2016		1,333
	2017		1,740
	2018		3,073
	2019		2,268
	2020 – 2024		24,159
	The above amounts were determined based on the non-executive employees’ current salary rates and the number of service years that will be accumulated upon their retirement dates. These amounts do not include amounts that might be paid to non-executive employees that will cease working with the Company before their normal retirement ages.

Foreign_Currency_Gain_Loss_Net

Foreign Currency Gain (Loss), Net	3 Months Ended
	Mar. 31, 2014
Foreign Currency [Abstract]
Foreign Currency Gain (Loss), Net	12. Foreign Currency Gain (Loss), Net
	Net foreign currency gain or loss includes non-cash translation gain or loss associated with intercompany balances. A substantial portion of the Company’s net foreign currency gain or loss is non-cash translation gain or loss associated with intercompany long-term loans to our Korean subsidiary. The loans are denominated in U.S. dollars and are affected by changes in the exchange rate between the Korean won and the U.S. dollar. As of March 31, 2014, the total intercompany loan balance was $529 million. The Korean won to U.S. dollar exchange rates were 1,068.8:1 and 1,055.3:1 using the first base rate as of March 31, 2014 and December 31, 2013, respectively, as quoted by the Korea Exchange Bank.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes
	The Company files income tax returns in the U.S., Korea, Japan, Taiwan and various other jurisdictions.
	The Company’s Korean subsidiary, MagnaChip Semiconductor, Ltd., is the principal operating entity within the consolidated Company. For the three months ended March 31, 2014 and 2013, no income tax expense for MagnaChip Semiconductor, Ltd. was recorded due to net operating loss carry-forwards available to offset taxable income and full allowance for deferred tax assets.
	Income tax expense recorded for the three months ended March 31, 2014 and 2013 was $803 thousand and $2,601 thousand (restated), respectively, primarily attributable to withholding taxes related to intercompany balances and net operating loss carry-back at the parent company and a domestic subsidiary.

Geographic_and_Segment_Informa

Geographic and Segment Information	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]
Geographic and Segment Information	14. Geographic and Segment Information
	The Company has one operating segment, consisting of three business lines: Display Solutions, Power Solutions and Semiconductor Manufacturing Services. The Company’s chief operating decision maker is considered to be its Chief Executive Officer. The chief operating decision maker allocates resources and assesses performance of the business and other activities at the operating segment level.
	The following is a summary of net sales by business line:
		Three Months Ended
		March 31,		March 31,
		2014		2013
				(As Restated)
	Net Sales
	Display Solutions	$	40,379	$	63,555
	Semiconductor Manufacturing Services		91,928		104,391
	Power Solutions		31,775		26,283
	All other		82		93
	Total net sales	$	164,164	$	194,322
	The following is a summary of net sales by region, based on the location of the customer:
		Three Months Ended
		March 31,		March 31,
		2014		2013
				(As Restated)
	Korea	$	67,013	$	84,446
	Asia Pacific (other than Korea)		70,221		68,511
	U.S.A.		19,753		28,690
	Europe		6,893		11,729
	Others		284		946
	Total	$	164,164	$	194,322
	Net sales from the Company’s top ten largest customers accounted for 55% and 67% for the three months ended March 31, 2014 and 2013, respectively.
	For the three months ended March 31, 2014, we had no customer which represented over 10% of the Company’s net sales.
	For the three months ended March 31, 2013, we had three customers which represented 16.0%, 11.0% and 10.9% of the Company’s net sales, respectively.
	Over 99% of the Company’s property, plant and equipment are located in Korea as of March 31, 2014.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2014
Text Block [Abstract]
Accumulated Other Comprehensive Loss	15. Accumulated Other Comprehensive Loss
	Accumulated other comprehensive loss consists of the following as of March 31, 2014 and December 31, 2013, respectively:
		March 31,			December 31,
		2014			2013
	Foreign currency translation adjustments	$	(50,707	)	$	(57,326	)
	Derivative adjustments		4,789			6,587
	Unrealized gain on investments		957			681
	Total	$	(44,961	)	$	(50,058	)
	Changes in accumulated other comprehensive loss for the three months ended March 31, 2014 and 2013 is as follows:
	Three Months Ended March 31, 2014	Foreign			Derivative			Unrealized		Total
		currency			adjustments			gain on
		translation						investments
		adjustments
	Beginning balance	$	(57,326	)	$	6,587		$	681	$	(50,058	)
	Other comprehensive income (loss) before reclassifications		6,619			(1,801	)		276		5,094
	Amounts reclassified from accumulated other comprehensive loss		—			3			—		3
	Net current-period other comprehensive income (loss)		6,619			(1,798	)		276		5,097
	Ending balance	$	(50,707	)	$	4,789		$	957	$	(44,961	)
	Three Months Ended March 31, 2013 (As Restated)	Foreign			Derivative			Unrealized		Total
		currency			adjustments			gain on
		translation						investments
		adjustments
	Beginning balance	$	(43,599	)	$	2,074		$	75	$	(41,450	)
	Other comprehensive income (loss) before reclassifications		13,733			(5,482	)		320		8,571
	Amounts reclassified from accumulated other comprehensive income		—			(250	)		—		(250	)
	Net current-period other comprehensive income (loss)		13,733			(5,732	)		320		8,321
	Ending balance	$	(29,866	)		(3,658	)	$	395	$	(33,129	)

Loss_per_Share

Loss per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]
Loss per Share	16. Loss per Share
	The following table illustrates the computation of basic and diluted loss per common share:
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Net loss	$	(21,605	)	$	(17,589	)
	Weighted average common stock outstanding
	Basic		34,052,875			35,539,413
	Diluted		34,052,875			35,539,413
	Loss per share
	Basic	$	(0.63	)	$	(0.49	)
	Diluted	$	(0.63	)	$	(0.49	)
	The following outstanding instruments were excluded from the computation of diluted loss per share, as they have an anti-dilutive effect on the calculation:
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Options		3,180,925			3,033,021
	Warrants		1,425,129			1,874,230

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. Commitments and Contingencies
	Matters Related to the Audit Committee’s Investigation, the Restatement of Certain of the Company’s Consolidated Financial Statements, the State of the Company’s Internal Control Over Financial Reporting and the Company’s Failure to Timely File Periodic Reports with the SEC
	Securities Class Action Complaint
	On March 12, 2014, a purported class action was filed against the Company and certain of the Company’s current and now-former officers on behalf of shareholders who purchased or acquired the Company’s securities between February 1, 2012 and March 11, 2014. On September 30, 2014, an amended complaint was filed against the Company, certain current and now-former officers of the Company, certain members of the Company’s Board of Directors, and a shareholder of the Company, alleging violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The action, Thomas et al., v. MagnaChip Semiconductor Corp., et al., No. 3:14-CV-1160, is pending in the Northern District of California. The Court has granted the plaintiffs thirty days from the date the 2013 Form 10-K is filed with the SEC to file and serve a further amended complaint. At this time, the Company is unable to estimate any reasonably possible loss, or range of reasonably possible losses, with respect to the matters described above.
	SEC Enforcement Staff Investigation
	In addition, in March 2014, the Company voluntarily reported to the SEC that the Audit Committee had determined that the Company incorrectly recognized revenue on certain transactions and as a result would restate its financial statements, and that the Audit Committee had commenced the Independent Investigation. Over the course of 2014, the Company voluntarily produced documents to the SEC regarding the various accounting issues identified during the Independent Investigation, and whether the Company’s hiring of an accountant from the Company’s independent registered public accounting firm impacted that accounting firm’s independence. On July 22, 2014, the Staff of the SEC’s Division of Enforcement obtained a Formal Order of Investigation. The Company will continue to cooperate with the SEC in this investigation. At this time, the Company is unable to estimate any reasonably possible loss, or range of reasonably possible losses, with respect to the matters described above.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	18. Subsequent Events
	Early termination of derivative contracts
	On September 1, 2014, the Company and the counterparty, the Goldman Sachs International bank (“GS”), mutually agreed to terminate a zero cost collar contract under termination provisions of the International Swaps and Derivatives Association (“ISDA”) agreement. In connection with this termination, the Company received $1,050 thousand for settlement proceeds from GS.
	On September 30, 2014, the Company and the counterparty, the UBS AG, Seoul Branch (“UBS”), mutually agreed to terminate a zero cost collar contract under termination provisions of the ISDA agreement. In connection with this termination, the Company received $430 thousand for settlement proceeds from UBS.
	Late Filings
	On November 12, 2014, we filed a Notification of Late Filing on Form 12b-25 with the SEC disclosing that we would be unable to timely file our Quarterly Report on Form 10-Q for the quarter ended September 30, 2014 with the SEC.
	Restatement
	On February 12, 2015, the Company filed with the SEC its 2013 Form 10-K containing audited financial statements of the Company for the year ended December 31, 2013 and audited restated financial statements for the years ended December 31, 2012 and 2011.
	NYSE Actions
	On April 4, 2014, we filed a Current Report on Form 8-K with the SEC announcing that on April 2, 2014 we received from NYSE Regulation, Inc. (the “NYSE”) a notice of failure to satisfy a continued listing rule or standard and related monitoring. The notice informed us that, as a result of our failure to timely file our 2013 Form 10-K, we are subject to the procedures specified in Section 802.01E (SEC Annual Report Timely Filing Criteria) of the NYSE Listed Company Manual (“Section 802.01E”). Under the Section 802.01E procedures, the NYSE will monitor the status of the filing of the 2013 Form 10-K and related public disclosures for up to a six-month period from its due date. If the Company did not file the 2013 Form 10-K within six months from the filing due date, the NYSE may, in its sole discretion, allow the Company’s common stock to trade for up to an additional six months pending the filing of the 2013 Form 10-K prior to commencing suspension or delisting procedures, depending on the Company’s specific circumstances.
	On September 5, 2014, we made a request to the NYSE that our shares be permitted to continue to trade on the NYSE while the Company completed its restatement of the consolidated financial statements. On October 3, 2014, we received an extension for continued listing and trading of the Company’s common stock on the NYSE. The extension, was subject to ongoing reassessment by the NYSE, provided the Company with an additional trading period until April 1, 2015, during which the Company can file its 2013 Form 10-K with the SEC. On February 12, 2015, the Company filed its 2013 Form 10-K, and simultaneously filed its Form 10-Q for each of the quarters ended March 31, 2014, June 30, 2014 and September, 30, 2014. The Company believes that these filings with the SEC satisfy the NYSE continued listing requirements.
	2021 Notes indenture reporting covenant default
	As disclosed in the Company’s Form 8-K filed on June 25, 2014, the Company received a notice of default on June 20, 2014 (the “10-K and Q1 10-Q Notice of Default”) from Wilmington Trust, National Association, as trustee, under the Indenture related to the 2021 Notes. The 10-K and Q1 10-Q Notice of Default related to the failure by the Company, pursuant to Section 4.03 of the Indenture, to file with the SEC its Annual Report on Form 10-K for the fiscal year ended December 31, 2013 and its Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2014 (the “Initial Reporting Defaults”). The Company did not cure the Initial Reporting Defaults within the applicable 60-day grace period and the Initial Reporting Defaults ripened into Events of Default. The Company elected, as the sole and exclusive remedy for the Events of Default, to pay additional interest on the 2021 Notes at a rate equal to 0.25% per annum of the principal amount of the 2021 Notes (the “Additional Interest”) for a period of 180 days following the occurrence of the Events of Default (the “Additional Interest Period”).
	On August 20, 2014, the Company received a notice of default related to its failure to file its Form 10-Q for the fiscal quarter ended June 30, 2014 (the “Q2 10-Q Notice of Default”), and on November 19, 2014, the Company received a notice of default related to its failure to file its Form 10-Q for the fiscal quarter ended September 30, 2014 (the “Q3 10-Q Notice of Default”). These defaults also ripened into Events of Default and on December 29, 2014 and January 15, 2015, respectively, the Company elected to extend the Additional Interest Period for up to 180 days following each additional Event of Default.
	Upon the filing with the SEC of the 2013 Form 10-K, this Report and the expected filing of the Form 10-Qs for the fiscal quarters ended June 30, 2014 and September 30, 2014, the Company believes it will regain compliance with its reporting obligations under the Indenture, cure all identified covenant defaults in each of the 10-K and Q1 10-Q Notice of Default, the Q2 10-Q Notice of Default, and the Q3 10-Q Notice of Default, and cease accruing the Additional Interest on the 2021 Notes as of the filing date of 10-Q for the fiscal quarter ended September 30, 2014.
	Close of a fabrication facility
	On December 4, 2014, the Company approved a plan to close its six-inch fabrication facility in Cheongju, South Korea (the “six-inch fab”). This plan is expected to be substantially implemented over the next 12 months, and the six-inch fab is expected to be closed by the end of 2015. The Company plans to transfer the six-inch fab employees to the Company’s other facilities.

Business_Basis_of_Presentation1

Business, Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]
Business	Business
	MagnaChip Semiconductor Corporation (together with its subsidiaries, the “Company”) is a Korea-based designer and manufacturer of analog and mixed-signal semiconductor products for high-volume consumer, computer and communication applications. The Company’s business is comprised of three key business lines: Display Solutions, Power Solutions and Semiconductor Manufacturing Services. The Company’s Display Solutions products include display drivers for use in a wide range of flat panel displays and mobile multimedia devices. The Company’s Power Solutions products include discrete and integrated circuit solutions for power management in high-volume consumer, computer, communication and industrial applications. The Company’s Semiconductor Manufacturing Services provide specialty analog and mixed-signal foundry services for fabless semiconductor companies that serve the consumer, computing and wireless end markets.
Basis of Presentation	Basis of Presentation
	The accompanying unaudited interim consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“US GAAP”). These interim consolidated financial statements include normal recurring adjustments and the elimination of all intercompany accounts and transactions which are, in the opinion of management, necessary to provide a fair statement of the Company’s financial condition and results of operations for the periods presented. These interim consolidated financial statements are presented in accordance with ASC 270, “Interim Reporting” (“ASC 270”) and, accordingly, do not include all of the information and note disclosures required by US GAAP for complete financial statements. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the results to be expected for a full year or for any other periods.
	The December 31, 2013 balance sheet data was derived from the Company’s audited financial statements, but does not include all disclosures required by US GAAP.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In August 2014, the FASB issued Accounting Standards Update No. 2014-15, “Presentation of Financial Statements — Going Concern” (“ASU 2014-15”), which provides guidance on determining when and how to disclose going-concern uncertainties in the financial statements. ASU 2014-15 requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued. An entity will be required to provide certain disclosures if conditions of events raise substantial doubt about the entity’s ability to continue as a going concern. ASU 2014-15 is effective for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2014-15 on its consolidated financial statements.
	In June 2014, the FASB issued Accounting Standards Update No. 2014-11, “Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures” (“ASU 2014-11”). The guidance in this update changes the accounting for repurchase-to-maturity transactions and repurchasing financing arrangements. It also requires enhanced disclosures about repurchase agreements and other similar transactions. The accounting changes in this update are effective for public companies for the first interim or annual period beginning after December 15, 2014. In addition, for public companies, the disclosure for certain transactions accounted for as a sale is effective for the first interim or annual period beginning on or after December 15, 2014, and the disclosure for transactions accounted for as secured borrowings is required to be presented for annual periods beginning after December 15, 2014, and interim periods beginning after March 15, 2015. Early application is not permitted. The Company is currently evaluating the impact of the adoption of ASU 2014-11 on its consolidated financial statements.
	In May 2014, the FASB issued Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”). ASU 2014-09 supersedes the revenue recognition requirements in “Revenue Recognition (Topic 605)”, and requires entities to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is not permitted. The Company is currently evaluating the impact of the adoption of ASU 2014-09 on its consolidated financial statements.

Restatement_of_Consolidated_Fi1

Restatement of Consolidated Financial Statements (Tables)	3 Months Ended
	Mar. 31, 2014
Accounting Changes and Error Corrections [Abstract]
Schedule of Impact of Restatement Adjustments on Previously Reported Consolidated Statements	The following table presents the impact of the restatement adjustments on the Company’s previously reported consolidated statement of operations for the three months ended March 31, 2013:
					Three Months Ended March 31, 2013
					Restatement Adjustments
		As Previously			Revenue			Inventory			Understated			Settlement		Tax			Maintenance			Cost			Account			Other			Total			As
		Reported			Recognition			Reserves			Employee			Obligations		Matters			Cost			Center			Classification			Adjustments			Adjustments			Restated
											Benefits											Allocation
	Net sales	$	205,298		$	(10,416	)	$	—		$	—		$	—	$	—		$	—		$	—		$	(560	)	$	—		$	(10,976	)	$	194,322
	Cost of sales		139,555			(8,647	)		3,860			132			—		—			2,432			(844	)		(404	)		3			(3,468	)		136,087
	Gross profit		65,743			(1,769	)		(3,860	)		(132	)		—		—			(2,432	)		844			(156	)		(3	)		(7,508	)		58,235
	Selling, general and administrative expenses		19,791			(89	)		—			19			—		180			—			860			—			47			1,017			20,808
	Research and development expenses		20,582			—			—			51			—		—			55			(16	)		404			(61	)		433			21,015
	Restructuring and impairment charges		2,446			—			—			—			—		—			—			—			—			—			—			2,446
	Operating income		22,924			(1,680	)		(3,860	)		(202	)		—		(180	)		(2,487	)		—			(560	)		11			(8,958	)		13,966
	Other income (expenses)
	Interest expense, net		(5,849	)		—			—			—			—		—			—			—			—			—			—			(5,849	)
	Foreign currency loss, net		(22,558	)		(907	)		—			—			—		—			—			—			—			7			(900	)		(23,458	)
	Others		(260	)		53			—			—			—		—			—			—			560			—			613			353
			(28,667	)		(854	)		—			—			—		—			—			—			560			7			(287	)		(28,954	)
	Loss before income taxes		(5,743	)		(2,534	)		(3,860	)		(202	)		—		(180	)		(2,487	)		—			—			18			(9,245	)		(14,988	)
	Income tax expenses		1,662			—			—			—			—		939			—			—			—			—			939			2,601
	Net loss	$	(7,405	)	$	(2,534	)	$	(3,860	)	$	(202	)	$	—	$	(1,119	)	$	(2,487	)	$	—		$	—		$	18		$	(10,184	)	$	(17,589	)
	Loss per common share—
	Basic	$	(0.21	)																														$	(0.49	)
	Diluted	$	(0.21	)																														$	(0.49	)
	Weighted average number of shares—
	Basic		35,539,413																																35,539,413
	Diluted		35,539,413																																35,539,413
	Note— Settlement Obligations column presented in the table above does not impact the statement operations for the three months ended March 2013.
	Statement of Cash Flows
	The following table presents the impact of the restatement adjustments on the Company’s consolidated statement of cash flow for three months ended March 31, 2013:
	Three Months Ended March 31, 2013
		As Previously			Restatement			As
		Reported			Adjustments			Restated
	Cash flows from operating activities
	Net loss	$	(7,405	)	$	(10,184	)	$	(17,589	)
	Adjustments to reconcile net loss to net cash provided by operating activities
	Depreciation and amortization		8,522			(131	)		8,391
	Provision for severance benefits		4,229			57			4,286
	Bad debt expenses		30			(42	)		(12	)
	Amortization of debt issuance costs and original issue discount		283			—			283
	Loss on foreign currency translation, net		28,280			899			29,179
	Restructuring and impairment charges		618			—			618
	Stock-based compensation		420			70			490
	Other		606			—			606
	Changes in operating assets and liabilities
	Accounts receivable		(6,409	)		10,147			3,738
	Inventories, net		2,022			(4,727	)		(2,705	)
	Other receivables		(1,278	)		12			(1,266	)
	Other current assets		2,014			1,515			3,529
	Deferred tax assets		2,182			(1,407	)		775
	Accounts payable		2,290			(154	)		2,136
	Other accounts payable		9,734			678			10,412
	Accrued expenses		(1,125	)		(77	)		(1,202	)
	Other current liabilities		(5,838	)		793			(5,045	)
	Other non-current liabilities		(957	)		1,291			334
	Payment of severance benefits		(627	)		—			(627	)
	Other		(47	)		(1	)		(48	)
	Net cash provided by operating activities		37,544			(1,261	)		36,283
	Cash flows from investing activities
	Purchase of plant, property and equipment		(32,927	)		1,275			(31,652	)
	Payment for intellectual property registration		(142	)		—			(142	)
	Payment of guarantee deposits		(741	)		—			(741	)
	Other		100			—			100
	Net cash used in investing activities		(33,710	)		1,275			(32,435	)
Cash flows from financing activities
Proceeds from issuance of common stock		1,006			—			1,006
Acquisition of treasury stock		(6,000	)		—			(6,000	)
Net cash used in financing activities		(4,994	)		—			(4,994	)
Effect of exchange rates on cash and cash equivalents		1,909			(14	)		1,895
Net increase in cash and cash equivalents		749			—			749
Cash and cash equivalents
Beginning of the period		182,238			—			182,238
End of the period	$	182,987		$	—		$	182,987
Supplemental cash flow information
Cash paid for interest	$	1		$	—		$	1
Cash paid for income taxes	$	6,384		$	(180	)	$	6,204
Non-cash investing activities
Property, plant and equipment additions in other accounts payable	$	—		$	1,101		$	1,101
Comprehensive Income
The following table presents the impact of the restatement adjustments on the Company’s previously reported consolidated statements of comprehensive income for the three months ended March 31, 2013:
	Three Months Ended
	March 31, 2013
	As Previously			As Restated
	Reported
Net loss	$	(7,405	)	$	(17,589	)
Other comprehensive income :
Foreign currency translation adjustments		9,133			13,733
Derivative adjustments
Fair valuation of derivatives		(4,207	)		(5,482	)
Reclassification adjustment for gain on derivatives included in net loss		(304	)		(250	)
Unrealized gain on investments		228			320
Total comprehensive loss	$	(2,555	)	$	(9,268	)

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories as of March 31, 2014 and December 31, 2013 consist of the following:
		March 31,			December 31,
		2014			2013
	Finished goods	$	48,596		$	43,734
	Semi-finished goods and work-in-process		94,061			92,030
	Raw materials		10,555			9,464
	Materials in-transit and other		750			1,870
	Less: inventory reserve		(70,265	)		(72,400	)
	Inventories, net	$	83,697		$	74,698
Changes in Inventory Reserve
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Beginning balance	$	(72,400	)	$	(25,429	)
	Change in reserve		(2,788	)		(7,777	)
	Write off		4,012			417
	Translation adjustments		911			1,125
	Ending balance	$	(70,265	)	$	(31,664	)

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment	Property, plant and equipment as of March 31, 2014 and December 31, 2013 comprise the following:
		March 31,			December 31,
		2014			2013
	Buildings and related structures	$	80,145		$	81,050
	Machinery and equipment		272,443			269,840
	Vehicles and others		23,333			22,397
			375,921			373,287
	Less: accumulated depreciation		(141,525	)		(136,397	)
	Land		17,188			17,407
	Property, plant and equipment, net	$	251,584		$	254,297

Intangible_Assets_Tables

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	Intangible assets as of March 31, 2014 and December 31, 2013 are as follows:
		March 31,			December 31,
		2014			2013
	Technology	$	19,827		$	20,081
	Customer relationships		29,072			29,444
	Intellectual property assets		7,827			7,829
	Less: accumulated amortization		(53,981	)		(54,243	)
	Intangible assets, net	$	2,745		$	3,111

Accrued_Expenses_Tables

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2014
Payables and Accruals [Abstract]
Summary of Accrued Expenses	Accrued expenses as of March 31, 2014 and December 31, 2013 are as follows:
		March 31,		December 31,
		2014		2013
	Payroll, benefits and related taxes,              excluding severance benefits	$	21,323	$	19,869
	Withholding tax levied on intercompany interest income		24,792		23,872
	Interest on senior notes		3,105		6,749
	Settlement obligations		4,677		6,460
	Outside service fees		3,457		1,462
	Others		7,407		7,082
	Accrued expenses	$	64,761	$	65,494

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Details of Derivative Contracts	Details of derivative contracts as of March 31, 2014 are as follows:
	Date of transaction	Type of derivative		Total notional amount				Month of settlement
	8-Mar-13	Zero cost collar		$	54,000			April to June 2014
	April 5, 2013	Zero cost collar		$	54,000			July to September 2014
	May 29, 2013	Zero cost collar		$	54,000			October to December 2014
	March 12, 2014	Zero cost collar		$	54,000			January to March 2015
Fair Value of Outstanding Zero Cost Collar Recorded as Assets	The fair values of the Company’s outstanding zero cost collar contracts recorded as assets as of March 31, 2014 and December 31, 2013 are as follows:
	Derivatives designated as hedging instruments:			March 31,				December 31,
				2014				2013
	Asset Derivatives:
	Zero cost collars	Other current assets		$	3,191			$	4,912
	Liabilities Derivatives:
	Zero cost collars	Other current liabilities		$	169			$	—
Offsetting of Derivative Assets	Offsetting of derivative assets as of March 31, 2014 and December 31, 2013 is as follows:
	As of March 31, 2014	Gross amounts of				Gross amounts				Net amounts of				Gross amounts not offset							Net amount
		recognized				offset in the				assets/liabilities				in the balance sheets
		assets/liabilities				balance sheets				presented in the
										balance sheets				Financial				Cash collateral
														instruments				received/
																		pledged
	Asset Derivatives:
	Zero cost collars	$	3,191			$	—			$	3,191			$	(169	)		$	—		$	3,022
	Liability Derivatives:
	Zero cost collars	$	169			$	—			$	169			$	(169	)		$	—		$	—
	As of December 31, 2013	Gross amounts of				Gross amounts				Net amounts of				Gross amounts not offset							Net amount
		recognized				offset in the				assets/liabilities				in the balance sheets
		assets/liabilities				balance sheets				presented in the
										balance sheets				Financial				Cash collateral
														instruments				received/
																		pledged
	Asset Derivatives:
	Zero cost collars	$	4,912			$	—			$	4,912			$	—			$	—		$	4,912
Impact of Derivative Instruments on Consolidated Statement of Operations	The following table summarizes the impact of derivative instruments on the consolidated statement of operations for the three months ended March 31, 2014 and 2013:
	Derivatives in ASC	Amount of Gain (Loss)								Location of		Amount of Gain (Loss)								Location of	Amount of Gain
	815 Cash Flow Hedging	Recognized in								Gain (Loss)		Reclassified from								Gain (Loss)	(Loss)
	Relationships	AOCI on								Reclassified from		AOCI into								Recognized in	Recognized in
		Derivatives								AOCI into		Statement of								Statement of	Statement of
		(Effective Portion)								Statement of		Operations								Operations on	Operations on
										Operations		(Effective Portion)								Derivative	Derivatives
										(Effective Portion)										(Ineffective	(Ineffective Portion
																				Portion and	and Amount
																				Amount	Excluded from
																				Excluded from	Effectiveness Testing)
																				Effectiveness
																				Testing)
		Three Months Ended										Three Months Ended									Three Months Ended
		March 31,										March 31,									March 31,
		2014				2013						2014				2013					2014			2013
						(As Restated)										(As Restated)								(As Restated)
	Zero cost collars	$	(1,801	)		$	(5,482	)		Net sales		$	(3	)		$	250			Other income	$	(16	)	$	(214	)
																				(expenses) —Others
	Total	$	(1,801	)		$	(5,482	)				$	(3	)		$	250				$	(16	)	$	(214	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The Company’s financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2014, and the basis for that measurement is as follows:
		Carrying Value		Fair Value		Quoted Prices in		Significant		Significant
				Measurement		Active Markets		Other		Unobservable
						for		Observable		Inputs
						Identical Asset		Inputs		(Level 3)
						(Level 1)		(Level 2)
	Assets:
	Available-for-sale securities	$	1,497	$	1,497	$	1,497	$	—	$	—
	Derivative assets (other current assets)		3,191		3,191		—		3,191		—
	Liabilities:
	Derivative liabilities (other current liabilities)		169		169		—		169		—

LongTerm_Borrowings_Tables

Long-Term Borrowings (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]
Components of Long-Term Borrowings	Long-term borrowings as of March 31, 2014 and December 31, 2013 are as follows:
		March 31,			December 31,
		2014			2013
	6.625% senior notes due July 2021	$	225,000		$	225,000
	Discount on senior notes		(1,049	)		(1,077	)
	Long-term borrowings, net of unamortized discount	$	223,951		$	223,923

Accrued_Severance_Benefits_Tab

Accrued Severance Benefits (Tables)	3 Months Ended
	Mar. 31, 2014
Postemployment Benefits [Abstract]
Changes in Accrued Severance Benefits	Changes in accrued severance benefits are as follows:
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Beginning balance	$	135,356		$	116,036
	Provisions		4,034			4,286
	Severance payments		(1,514	)		(627	)
	Translation adjustments		(1,700	)		(4,377	)
			136,176			115,318
	Less: Cumulative contributions to the National Pension Fund		(375	)		(379	)
	Group severance insurance plan		(788	)		(754	)
	Accrued severance benefits, net	$	135,013		$	114,185
Future Benefits Payments to Employees	The Company is liable to pay the following future benefits to its non-executive employees upon their normal retirement age:
		Severance benefit
	Remainder of 2014	$	374
	2015		390
	2016		1,333
	2017		1,740
	2018		3,073
	2019		2,268
	2020 – 2024		24,159

Geographic_and_Segment_Informa1

Geographic and Segment Information (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]
Net Sales by Business Line	The following is a summary of net sales by business line:
		Three Months Ended
		March 31,		March 31,
		2014		2013
				(As Restated)
	Net Sales
	Display Solutions	$	40,379	$	63,555
	Semiconductor Manufacturing Services		91,928		104,391
	Power Solutions		31,775		26,283
	All other		82		93
	Total net sales	$	164,164	$	194,322
Net Sales by Region, Based on Location of Customer	The following is a summary of net sales by region, based on the location of the customer:
		Three Months Ended
		March 31,		March 31,
		2014		2013
				(As Restated)
	Korea	$	67,013	$	84,446
	Asia Pacific (other than Korea)		70,221		68,511
	U.S.A.		19,753		28,690
	Europe		6,893		11,729
	Others		284		946
	Total	$	164,164	$	194,322

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2014
Text Block [Abstract]
Schedule of Accumulated Other Comprehensive Loss	Accumulated other comprehensive loss consists of the following as of March 31, 2014 and December 31, 2013, respectively:
		March 31,			December 31,
		2014			2013
	Foreign currency translation adjustments	$	(50,707	)	$	(57,326	)
	Derivative adjustments		4,789			6,587
	Unrealized gain on investments		957			681
	Total	$	(44,961	)	$	(50,058	)
Changes in Accumulated Other Comprehensive Loss	Changes in accumulated other comprehensive loss for the three months ended March 31, 2014 and 2013 is as follows:
	Three Months Ended March 31, 2014	Foreign			Derivative			Unrealized		Total
		currency			adjustments			gain on
		translation						investments
		adjustments
	Beginning balance	$	(57,326	)	$	6,587		$	681	$	(50,058	)
	Other comprehensive income (loss) before reclassifications		6,619			(1,801	)		276		5,094
	Amounts reclassified from accumulated other comprehensive loss		—			3			—		3
	Net current-period other comprehensive income (loss)		6,619			(1,798	)		276		5,097
	Ending balance	$	(50,707	)	$	4,789		$	957	$	(44,961	)
	Three Months Ended March 31, 2013 (As Restated)	Foreign			Derivative			Unrealized		Total
		currency			adjustments			gain on
		translation						investments
		adjustments
	Beginning balance	$	(43,599	)	$	2,074		$	75	$	(41,450	)
	Other comprehensive income (loss) before reclassifications		13,733			(5,482	)		320		8,571
	Amounts reclassified from accumulated other comprehensive income		—			(250	)		—		(250	)
	Net current-period other comprehensive income (loss)		13,733			(5,732	)		320		8,321
	Ending balance	$	(29,866	)		(3,658	)	$	395	$	(33,129	)

Loss_per_Share_Tables

Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]
Table Illustrating Computation of Basic and Diluted Loss per Common Share	The following table illustrates the computation of basic and diluted loss per common share:
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Net loss	$	(21,605	)	$	(17,589	)
	Weighted average common stock outstanding
	Basic		34,052,875			35,539,413
	Diluted		34,052,875			35,539,413
	Loss per share
	Basic	$	(0.63	)	$	(0.49	)
	Diluted	$	(0.63	)	$	(0.49	)
Table Showing Outstanding Options and Warrants Excluded from Computation of Diluted Loss per Share	The following outstanding instruments were excluded from the computation of diluted loss per share, as they have an anti-dilutive effect on the calculation:
		Three Months Ended
		March 31,			March 31,
		2014			2013
					(As Restated)
	Options		3,180,925			3,033,021
	Warrants		1,425,129			1,874,230

Business_Basis_of_Presentation2

Business, Basis of Presentation and Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014
	Business_Lines
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business lines	3

Restatement_of_Consolidated_Fi2

Restatement of Consolidated Financial Statements - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012
Decrease in cost of sales	$123,887	$136,087
Income tax adjustments			112
Adjustments [Member]
Decrease in cost of sales		-3,468
Adjustments [Member] | Manufacturing Costs, Fabrication and Back-End Processing [Member]
Decrease in cost of sales		-1,400
As Previously Reported [Member]
Decrease in cost of sales		139,555
Deferred tax assets valuation allowance			$64,749

Restatement_of_Consolidated_Fi3

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

Restatement_of_Consolidated_Fi4

Restatement of Consolidated Financial Statements - Schedule of Impact of Restatement Adjustments on Consolidated Statement of Cash Flow (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	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

Restatement_of_Consolidated_Fi5

Restatement of Consolidated Financial Statements - Schedule of Impact of Restatement Adjustments on Previously Reported Consolidated Statements of Comprehensive Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net loss	($21,605)	($17,589)
Other comprehensive income :
Foreign currency translation adjustments	6,619	13,733
Derivative adjustments
Fair valuation of derivatives	-1,801	-5,482
Reclassification adjustment for gain on derivatives included in net loss	3	-250
Unrealized gain on investments	276	320
Total comprehensive loss	-16,508	-9,268
As Previously Reported [Member]
Net loss		-7,405
Other comprehensive income :
Foreign currency translation adjustments		9,133
Derivative adjustments
Fair valuation of derivatives		-4,207
Reclassification adjustment for gain on derivatives included in net loss		-304
Unrealized gain on investments		228
Total comprehensive loss		($2,555)

Sales_of_Accounts_Receivable_a1

Sales of Accounts Receivable and Receivable Discount Program - Additional Information (Detail) (Trade Accounts Receivable [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of accounts receivable	$3,139	$10,072
Pre-tax loss on accounts receivable	$8	$20

Inventories_Summary_of_Invento

Inventories - Summary of Inventories (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Finished goods	$48,596	$43,734
Semi-finished goods and work-in-process	94,061	92,030
Raw materials	10,555	9,464
Materials in-transit and other	750	1,870
Less: inventory reserve	-70,265	-72,400	-31,664	-25,429
Inventories, net	$83,697	$74,698

Inventories_Changes_in_Invento

Inventories - Changes in Inventory Reserve (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Inventory Disclosure [Abstract]
Beginning balance	($72,400)	($25,429)
Change in reserve	-2,788	-7,777
Write off	4,012	417
Translation adjustments	911	1,125
Ending balance	($70,265)	($31,664)

Property_Plant_and_Equipment_S

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$375,921	$373,287
Less: accumulated depreciation	-141,525	-136,397
Land	17,188	17,407
Property, plant and equipment, net	251,584	254,297
Buildings and related structures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	80,145	81,050
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	272,443	269,840
Vehicles and others [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$23,333	$22,397

Intangible_Assets_Summary_of_I

Intangible Assets - Summary of Intangible Assets (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]
Less: accumulated amortization	($53,981)	($54,243)
Intangible assets, net	2,745	3,111
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	19,827	20,081
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	29,072	29,444
Intellectual property assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$7,827	$7,829

Accrued_Expenses_Summary_of_Ac

Accrued Expenses - Summary of Accrued Expenses (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Payroll, benefits and related taxes, excluding severance benefits	$21,323	$19,869
Withholding tax levied on intercompany interest income	24,792	23,872
Interest on senior notes	3,105	6,749
Settlement obligations	4,677	6,460
Outside service fees	3,457	1,462
Others	7,407	7,082
Accrued expenses	$64,761	$65,494

Accrued_Expenses_Additional_In

Accrued Expenses - Additional Information (Detail) (Other non-current liabilities [Member], USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Other non-current liabilities [Member]
Accrued Liabilities [Line Items]
Settlement obligations	$6,037

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Details of Derivative Contracts (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Zero cost collar one [Member]
Derivative [Line Items]
Date of transaction	8-Mar-13
Type of derivative	Zero cost collar
Total notional amount	$54,000
Month of settlement	April to June 2014
Zero cost collar two [Member]
Derivative [Line Items]
Date of transaction	5-Apr-13
Type of derivative	Zero cost collar
Total notional amount	54,000
Month of settlement	July to September 2014
Zero cost collar three [Member]
Derivative [Line Items]
Date of transaction	29-May-13
Type of derivative	Zero cost collar
Total notional amount	54,000
Month of settlement	October to December 2014
Zero cost collar four [Member]
Derivative [Line Items]
Date of transaction	12-Mar-14
Type of derivative	Zero cost collar
Total notional amount	$54,000
Month of settlement	January to March 2015

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Fair Value of Outstanding Zero Cost Collar Recorded as Assets (Detail) (Derivative designated as hedging instruments [Member], Zero cost collars [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other current assets [Member]
Asset Derivatives:
Derivatives designated as hedging instruments, Asset	$3,191	$4,912
Other current liabilities [Member]
Liabilities Derivatives:
Derivatives designated as hedging instruments, Liability	$169

Derivative_Financial_Instrumen4

Derivative Financial Instruments - Offsetting of Derivative Assets (Detail) (Zero cost collars [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Zero cost collars [Member]
Derivative [Line Items]
Asset Derivatives, Gross amounts of recognized assets/liabilities	$3,191	$4,912
Liability Derivatives, Gross amounts of recognized assets/liabilities	169
Asset Derivatives, Gross amounts offset in the balance sheets	0	0
Liability Derivatives, Gross amounts offset in the balance sheets	0
Asset Derivatives, Net amounts of assets/liabilities presented in the balance sheets	3,191	4,912
Liability Derivatives, Net amounts of assets/liabilities presented in the balance sheets	169
Asset Derivatives, Gross amounts not offset in the balance sheets, Financial instruments	-169
Liability Derivatives, Gross amounts not offset in the balance sheets, Financial instruments	-169
Asset Derivatives, Gross amounts not offset in the balance sheets, Cash collateral received/pledged	0	0
Liability Derivatives, Gross amounts not offset in the balance sheets, Cash collateral received/pledged	0
Asset Derivatives, Gross amounts not offset in the balance sheets, Net amount	3,022	4,912
Liability Derivatives, Gross amounts not offset in the balance sheets, Net amount	$0

Derivative_Financial_Instrumen5

Derivative Financial Instruments - Impact of Derivative Instruments on Consolidated Statement of Operations (Detail) (Derivatives in ASC 815 Cash Flow Hedging Relationships [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Derivative [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	($1,801)	($5,482)
Other income (expenses) - Others [Member]
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Statement of Operations on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	-16	-214
Net sales [Member]
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Statement of Operations (Effective Portion)	-3	250
Zero cost collars [Member]
Derivative [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	-1,801	-5,482
Zero cost collars [Member] | Other income (expenses) - Others [Member]
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Statement of Operations on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	-16	-214
Zero cost collars [Member] | Net sales [Member]
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Statement of Operations (Effective Portion)	($3)	$250

Derivative_Financial_Instrumen6

Derivative Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Amount reclassified from accumulated other comprehensive income into earnings, period	12 months
Amount reclassified from accumulated other comprehensive income into earnings	$2,912,000
Cash and cash equivalents	30,000,000
Deposit of cash collateral in excess	5,000,000
Cash collateral for credit support to counterparties	$0

Fair_Value_Measurements_Financ

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (Assets and liabilities measured at fair value on recurring basis [Member], USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Quoted Prices in Active Markets for Identical Asset (Level 1) [Member]
Assets:
Available-for-sale securities	$1,497
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Derivative assets (other current assets)	3,191
Liabilities:
Derivative liabilities (other current liabilities)	169
Carrying Value [Member]
Assets:
Available-for-sale securities	1,497
Derivative assets (other current assets)	3,191
Liabilities:
Derivative liabilities (other current liabilities)	169
Fair Value Measurement [Member]
Assets:
Available-for-sale securities	1,497
Derivative assets (other current assets)	3,191
Liabilities:
Derivative liabilities (other current liabilities)	$169

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Jul. 18, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount of senior notes	$223,951	223,923
6.625% senior notes due 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes, percentage	6.63%	6.63%	6.63%
Senior Notes, maturity year	2021
Carrying amount of senior notes	223,951
Estimated fair value of senior notes	$225,563

Longterm_Borrowings_Components

Long-term Borrowings - Components of Long-Term Borrowings (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Jul. 18, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Discount on senior notes	($1,049)	($1,077)
Long-term borrowings, net of unamortized discount	223,951	223,923
6.625% senior notes due 2021 [Member]
Debt Instrument [Line Items]
Long-term borrowings	225,000	225,000
Discount on senior notes			-1,100
Long-term borrowings, net of unamortized discount	$223,951

Longterm_Borrowings_Components1

Long-term Borrowings - Components of Long-Term Borrowings (Parenthetical) (Detail) (6.625% senior notes due 2021 [Member])	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Jul. 18, 2013
6.625% senior notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate	6.63%	6.63%	6.63%
Due date	15-Jul-21	15-Jul-21

Longterm_Borrowings_Additional

Long-term Borrowings - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended
	Jul. 18, 2013	Mar. 31, 2014	Dec. 31, 2013	Jul. 18, 2013
Debt Instrument [Line Items]
Original debt issue discount		$1,049,000	1,077,000
6.625% senior notes due 2021 [Member]
Debt Instrument [Line Items]
Aggregate principal amount	225,000,000			225,000,000
Interest rate	6.63%	6.63%	6.63%	6.63%
Due date		15-Jul-21	15-Jul-21
Aggregate principal amount of senior notes pricing	99.50%
Net proceeds from senior notes	218,800,000
Original debt issue discount	1,100,000			1,100,000
Debt issuance costs paid	5,100,000
Loss on early extinguishment of senior notes		32,800,000
Repurchase premium on senior notes		23,800,000
Write-off of discounts, senior notes		1,900,000
Write-off of debt issuance costs		5,300,000
Interest incurred during the period		1,800,000
Percentage of redeem aggregate principal amount of Notes issued		35.00%
Redemption price plus accrued, unpaid interest and special interest to the date of redemption		106.63%
Redemption price		100.00%
6.625% senior notes due 2021 [Member] | 2017 [Member]
Debt Instrument [Line Items]
Redemption price plus accrued, unpaid interest and special interest to the date of redemption		103.31%
6.625% senior notes due 2021 [Member] | 2018 [Member]
Debt Instrument [Line Items]
Redemption price plus accrued, unpaid interest and special interest to the date of redemption		101.66%
6.625% senior notes due 2021 [Member] | 2019 [Member]
Debt Instrument [Line Items]
Redemption price plus accrued, unpaid interest and special interest to the date of redemption		100.00%
6.625% senior notes due 2021 [Member] | Other non-current assets [Member]
Debt Instrument [Line Items]
Remaining capitalized costs		4,700,000
6.625% senior notes due 2021 [Member] | Amortization costs [Member]
Debt Instrument [Line Items]
Interest expense, net		$123,000
10.5% senior notes due 2018 [Member]
Debt Instrument [Line Items]
Interest rate		10.50%
Due date		15-Apr-18

Accrued_Severance_Benefits_Add

Accrued Severance Benefits - Additional Information (Detail)	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Eligible employees for severance benefits	98.00%

Accrued_Severance_Benefits_Cha

Accrued Severance Benefits - Changes in Accrued Severance Benefits (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Accrued severance benefits, net	$135,013		$134,172
Employee severance [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	135,356	116,036
Provisions	4,034	4,286
Severance payments	-1,514	-627
Translation adjustments	-1,700	-4,377
Ending balance	136,176	115,318
Less: Cumulative contributions to the National Pension Fund	-375	-379
Group severance insurance plan	-788	-754
Accrued severance benefits, net	$135,013	$114,185

Accrued_Severance_Benefits_Fut

Accrued Severance Benefits - Future Benefits Payments to Employees (Detail) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Compensation and Retirement Disclosure [Abstract]
Remainder of 2014	$374
2015	390
2016	1,333
2017	1,740
2018	3,073
2019	2,268
2020 - 2024	$24,159

Foreign_Currency_Gain_Loss_Net1

Foreign Currency Gain (Loss), Net - Additional Information (Detail)	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	USD ($)	KRW	KRW
Foreign Currency Transaction [Abstract]
Exchange rates using first base rate		1,068.80	1,055.30
Intercompany loan balance	$529

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$803,000	$2,601,000
MagnaChip Semiconductor, Ltd. [Member]
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$0	$0

Geographic_and_Segment_Informa2

Geographic and Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
	Customer	Customer
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments	1
Number of business lines	3
Customer Concentration Risk [Member] | Net Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	10.00%
Number of customers	0
Customer Concentration Risk [Member] | Net Sales [Member] | Top Ten Customers [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	55.00%	67.00%
Number of customers	10	10
Customer Concentration Risk [Member] | Net Sales [Member] | Customer One [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage		16.00%
Customer Concentration Risk [Member] | Net Sales [Member] | Customer Two [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage		11.00%
Customer Concentration Risk [Member] | Net Sales [Member] | Customer Three [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage		10.90%
Geographic Concentration Risk [Member] | Property, Plant and Equipment [Member] | Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk, percentage	99.00%

Geographic_and_Segment_Informa3

Geographic and Segment Information - Net Sales by Business Line (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net Sales
Total net sales	$164,164	$194,322
Display Solutions [Member]
Net Sales
Total net sales	40,379	63,555
Semiconductor Manufacturing Services [Member]
Net Sales
Total net sales	91,928	104,391
Power Solutions [Member]
Net Sales
Total net sales	31,775	26,283
All Other [Member]
Net Sales
Total net sales	$82	$93

Geographic_and_Segment_Informa4

Geographic and Segment Information - Net Sales by Region, Based on Location of Customer (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$164,164	$194,322
Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	67,013	84,446
Asia Pacific (other than Korea) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	70,221	68,511
U.S.A. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	19,753	28,690
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	6,893	11,729
Others [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$284	$946

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Equity [Abstract]
Foreign currency translation adjustments	($50,707)	($57,326)
Derivative adjustments	4,789	6,587
Unrealized gain on investments	957	681
Total	($44,961)	($50,058)	($33,129)	($41,450)

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	($50,058)	($41,450)
Other comprehensive income (loss) before reclassifications	5,094	8,571
Amounts reclassified from accumulated other comprehensive loss (income)	3	-250
Net current-period other comprehensive income (loss)	5,097	8,321
Ending balance	-44,961	-33,129
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	-57,326	-43,599
Other comprehensive income (loss) before reclassifications	6,619	13,733
Net current-period other comprehensive income (loss)	6,619	13,733
Ending balance	-50,707	-29,866
Derivative adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	6,587	2,074
Other comprehensive income (loss) before reclassifications	-1,801	-5,482
Amounts reclassified from accumulated other comprehensive loss (income)	3	-250
Net current-period other comprehensive income (loss)	-1,798	-5,732
Ending balance	4,789	-3,658
Unrealized gain on investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	681	75
Other comprehensive income (loss) before reclassifications	276	320
Net current-period other comprehensive income (loss)	276	320
Ending balance	$957	$395

Loss_per_Share_Table_Illustrat

Loss per Share - Table Illustrating Computation of Basic and Diluted Loss per Common Share (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Net loss	($21,605)	($17,589)
Weighted average common stock outstanding
Basic	34,052,875	35,539,413
Diluted	34,052,875	35,539,413
Loss per share
Basic	($0.63)	($0.49)
Diluted	($0.63)	($0.49)

Loss_per_Share_Table_Showing_O

Loss per Share - Table Showing Outstanding Options and Warrants Excluded from Computation of Diluted Loss per Share (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding units and warrants excluded from computation of diluted earnings (loss) per share/unit	3,180,925	3,033,021
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding units and warrants excluded from computation of diluted earnings (loss) per share/unit	1,425,129	1,874,230

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	3 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2014	Sep. 01, 2014
6.625% senior notes due 2021 [Member]
Subsequent Event [Line Items]
Debt instrument, covenant terms	Company did not cure the Initial Reporting Defaults within the applicable 60-day grace period and the Initial Reporting Defaults ripened into Events of Default.
Debt acceleration period	180 days
Interest rate additional to base rate	0.25%
Subsequent Event [Member] | UBS AG Seoul Branch [Member]
Subsequent Event [Line Items]
Settlement proceeds		$430
Subsequent Event [Member] | Goldman Sachs International bank [Member]
Subsequent Event [Line Items]
Settlement proceeds			$1,050