Condensed Consolidating Financial Information - Condensed Consolidating Statement of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flow from operating activities
Net income (loss)	$ 68,015	$ (1,912)
Adjustments to reconcile net Income (loss) to net cash provided by (used in) operating activities
Depreciation and amortization	23,840	42,368
Provision for severance benefits	16,779	13,137
Amortization of debt issuance costs	753	728
(Gain)loss on foreign currency translation, net	(25,304)	33,220
Loss on disposal of property, plant and equipment	(174)	(15)
Loss on disposal of intangible assets, net	26	17
Restructuring and impairment charges		4,096
Stock-based compensation	1,450	1,798
Other	(332)	6,111
Changes in operating assets and liabilities
Accounts receivable, net	(18,168)	(4,400)
Inventories, net	(8,526)	(4,400)
Other receivables	(1,787)	836
Other current assets	(662)	(3,196)
Deferred tax assets	1,514	1,483
Accounts payable	17,472	15,072
Other accounts payable	(700)	7,157
Accrued expenses	13,761	(18,278)
Other current liabilities	9,450	(1,209)
Payment of severance benefits	(5,569)	(6,549)
Other	(2,239)	141
Net cash provided by (used in) operating activities	89,599	86,205
Cash flows from investing activities
Decrease (increase) in restricted cash	6,774	(9,711)
Decrease in short-term loans		(225)
Proceeds from disposal of plant, property and equipment	937	29
Purchases of plant, property and equipment	(56,745)	(42,945)
Payment for intellectual property registration	(752)	(521)
Payment for purchase of Dawin, net of cash acquired	(8,642)
Decrease in short-term financial instruments	173
Collection of guarantee deposits	72	984
Payment of guarantee deposits	(311)	(2,489)
Other	(50)	(400)
Net cash provided by (used in) investing activities	(58,544)	(55,278)
Cash flow from financing activities
Proceeds from issuance of common stock	436	8,835
Repayment of long-term borrowings		(50,307)
Repayment of obligations under capital lease	(2,968)	(4,831)
Acquisition of treasury stock	(22,937)
Net cash provided by (used in) financing activities	(25,469)	(46,303)
Effect of exchange rates on cash and cash equivalents	(2,039)	2,672
Net increase (decrease) in cash and cash equivalents	3,547	(12,704)
Cash and cash equivalents
Beginning of the period	162,111	172,172
End of the period	165,658	159,468
MagnaChip Semiconductor Corporation (Parent) [Member]
Cash flow from operating activities
Net income (loss)	68,015	(1,912)
Adjustments to reconcile net Income (loss) to net cash provided by (used in) operating activities
(Gain)loss on foreign currency translation, net	(158)
Stock-based compensation	(95)	178
Equity in earnings (loss) of related investment	(54,817)	1,737
Other		(1,474)
Changes in operating assets and liabilities
Other receivables	1	706
Other current assets	(19,667)	194
Other accounts payable	24,727	(7,041)
Accrued expenses	(325)	106
Other current liabilities	4,041
Other	(71)
Net cash provided by (used in) operating activities	21,651	(7,506)
Cash flow from financing activities
Proceeds from issuance of common stock	436	8,835
Acquisition of treasury stock	(22,937)
Net cash provided by (used in) financing activities	(22,501)	8,835
Net increase (decrease) in cash and cash equivalents	(850)	1,329
Cash and cash equivalents
Beginning of the period	1,677	79
End of the period	827	1,408
Co-Issuers [Member]
Cash flow from operating activities
Net income (loss)	54,604	(1,501)
Adjustments to reconcile net Income (loss) to net cash provided by (used in) operating activities
Amortization of debt issuance costs	753	728
(Gain)loss on foreign currency translation, net	724	(3,696)
Equity in earnings (loss) of related investment	(52,661)	29,153
Other	2	5,461
Changes in operating assets and liabilities
Other receivables	(24,483)	718
Other current assets	(38,313)	(48,027)
Other accounts payable	35	(8,555)
Accrued expenses	24,490	3,987
Net cash provided by (used in) operating activities	(34,849)	(21,732)
Cash flows from investing activities
Decrease in short-term loans		51,132
Other	21,983
Net cash provided by (used in) investing activities	21,983	51,132
Cash flow from financing activities
Repayment of long-term borrowings		(50,307)
Net cash provided by (used in) financing activities		(50,307)
Net increase (decrease) in cash and cash equivalents	(12,866)	(20,907)
Cash and cash equivalents
Beginning of the period	25,119	46,595
End of the period	12,253	25,688
Non-Guarantors [Member]
Cash flow from operating activities
Net income (loss)	61,256	(13,388)
Adjustments to reconcile net Income (loss) to net cash provided by (used in) operating activities
Depreciation and amortization	23,704	42,161
Provision for severance benefits	16,740	12,959
(Gain)loss on foreign currency translation, net	(25,380)	31,387
Loss on disposal of property, plant and equipment	(191)	(15)
Loss on disposal of intangible assets, net	26	17
Restructuring and impairment charges		2,409
Stock-based compensation	1,536	1,442
Other	(340)	1,133
Changes in operating assets and liabilities
Accounts receivable, net	(18,614)	35,467
Inventories, net	(8,526)	(4,413)
Other receivables	(549)	11,349
Other current assets	(729)	(1,977)
Accounts payable	17,594	(19,617)
Other accounts payable	(52)	4,966
Accrued expenses	37,814	18,065
Other current liabilities	1,390	(252)
Payment of severance benefits	(5,569)	(6,510)
Other	3,587	2,681
Net cash provided by (used in) operating activities	103,697	117,865
Cash flows from investing activities
Decrease (increase) in restricted cash	6,774	(9,711)
Decrease in short-term loans		19
Proceeds from disposal of plant, property and equipment	937	29
Purchases of plant, property and equipment	(56,694)	(42,911)
Payment for intellectual property registration	(752)	(521)
Payment for purchase of Dawin, net of cash acquired	(8,642)
Decrease in short-term financial instruments	173
Collection of guarantee deposits	42	979
Payment of guarantee deposits	(309)	(2,479)
Other	(41)	(400)
Net cash provided by (used in) investing activities	(58,512)	(54,995)
Cash flow from financing activities
Repayment of long-term intercompany borrowings	(21,746)
Repayment of long-term borrowings		(53,331)
Repayment of obligations under capital lease	(2,968)	(4,607)
Net cash provided by (used in) financing activities	(24,714)	(57,938)
Effect of exchange rates on cash and cash equivalents	(1,668)	4,042
Net increase (decrease) in cash and cash equivalents	18,803	8,974
Cash and cash equivalents
Beginning of the period	127,118	112,370
End of the period	145,921	121,344
Guarantors [Member]
Cash flow from operating activities
Net income (loss)	52,873	(29,389)
Adjustments to reconcile net Income (loss) to net cash provided by (used in) operating activities
Depreciation and amortization	136	207
Provision for severance benefits	39	178
(Gain)loss on foreign currency translation, net	(490)	5,529
Loss on disposal of property, plant and equipment	17
Restructuring and impairment charges		1,687
Stock-based compensation	9	470
Equity in earnings (loss) of related investment	(61,255)	13,400
Other	6	1,845
Changes in operating assets and liabilities
Accounts receivable, net	(205)	35,630
Other receivables	31	2,563
Other current assets	(29,003)	(41,859)
Deferred tax assets	1,514	1,051
Accounts payable	301	(40,821)
Other accounts payable	(1,875)	3,287
Accrued expenses	38,739	48,050
Other current liabilities	4,019	(957)
Payment of severance benefits		(39)
Other	(6,073)	(2,988)
Net cash provided by (used in) operating activities	(1,217)	(2,156)
Cash flows from investing activities
Decrease in short-term loans		38,452
Purchases of plant, property and equipment	(51)	(34)
Collection of guarantee deposits	30	5
Payment of guarantee deposits	(2)	(10)
Other	21,373
Net cash provided by (used in) investing activities	21,350	38,413
Cash flow from financing activities
Repayment of long-term intercompany borrowings	(21,983)
Repayment of long-term borrowings		(38,466)
Repayment of obligations under capital lease		(224)
Net cash provided by (used in) financing activities	(21,983)	(38,690)
Effect of exchange rates on cash and cash equivalents	310	333
Net increase (decrease) in cash and cash equivalents	(1,540)	(2,100)
Cash and cash equivalents
Beginning of the period	8,197	13,128
End of the period	6,657	11,028
Eliminations [Member]
Cash flow from operating activities
Net income (loss)	(168,733)	44,278
Adjustments to reconcile net Income (loss) to net cash provided by (used in) operating activities
Restructuring and impairment charges		(1)
Stock-based compensation		(292)
Equity in earnings (loss) of related investment	168,733	(44,290)
Other		(854)
Changes in operating assets and liabilities
Accounts receivable, net	651	(75,497)
Inventories, net		13
Other receivables	23,213	(14,500)
Other current assets	87,050	88,473
Deferred tax assets		432
Accounts payable	(423)	75,510
Other accounts payable	(23,535)	14,500
Accrued expenses	(86,957)	(88,486)
Other	318	448
Net cash provided by (used in) operating activities	317	(266)
Cash flows from investing activities
Decrease in short-term loans		(89,828)
Other	(43,365)
Net cash provided by (used in) investing activities	(43,365)	(89,828)
Cash flow from financing activities
Repayment of long-term intercompany borrowings	43,729
Repayment of long-term borrowings		91,797
Net cash provided by (used in) financing activities	43,729	91,797
Effect of exchange rates on cash and cash equivalents	$ (681)	$ (1,703)