Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current assets
Cash and cash equivalents	$ 182,238	$ 162,111	$ 172,172	$ 64,925
Restricted cash	133	6,830
Accounts receivable, net	143,331	125,922
Inventories, net	89,363	62,836
Other receivables	1,429	256
Prepaid expenses	7,884	6,032
Current deferred income tax assets	22,768	3,406
Other current assets	9,680	12,503
Total current assets	456,826	379,896
Property, plant and equipment, net	238,256	182,663
Intangible assets, net	15,260	16,787
Long-term prepaid expenses	18,048	4,790
Deferred income tax assets	46,710	3,537
Other non-current assets	14,866	15,002
Total assets	789,966	602,675
Current liabilities
Accounts payable	79,236	77,848
Other accounts payable	15,600	13,452
Accrued expenses	43,486	31,723
Current portion of capital lease obligations		2,852
Other current liabilities	9,973	2,007
Total current liabilities	148,295	137,639
Long-term borrowings	201,653	201,389
Accrued severance benefits, net	112,446	90,755
Other non-current liabilities	17,263	6,222
Total liabilities	479,657	436,005
Commitments and contingencies
Stockholders' equity
Common stock	396	394
Additional paid-in capital	101,885	98,929
Retained earnings	287,251	93,950
Treasury stock	(39,918)	(11,793)
Accumulated other comprehensive loss	(39,305)	(14,810)
Total stockholders' equity	310,309	166,670	162,851	215,690
Total liabilities and stockholders' equity	789,966	602,675
MagnaChip Semiconductor Corporation (Parent) [Member]
Current assets
Cash and cash equivalents	2,193	1,677	79	136
Other receivables	363	1
Prepaid expenses	36	34
Other current assets	84,045	58,636
Total current assets	86,637	60,348
Investment in subsidiaries	(422,475)	(576,642)
Long-term intercompany loan	697,125	697,125
Total assets	361,287	180,831
Current liabilities
Other accounts payable	44,438	13,659
Accrued expenses	308	502
Other current liabilities	6,232
Total current liabilities	50,978	14,161
Total liabilities	50,978	14,161
Commitments and contingencies
Stockholders' equity
Common stock	396	394
Additional paid-in capital	101,885	98,929
Retained earnings	287,251	93,950
Treasury stock	(39,918)	(11,793)
Accumulated other comprehensive loss	(39,305)	(14,810)
Total stockholders' equity	310,309	166,670
Total liabilities and stockholders' equity	361,287	180,831
Co-Issuers [Member]
Current assets
Cash and cash equivalents	10,539	25,119	46,595	24
Other receivables	42,276	11,793
Prepaid expenses		2
Other current assets	243,989	188,018
Total current assets	296,804	224,932
Investment in subsidiaries	(513,236)	(655,845)
Long-term intercompany loan	776,369	809,913
Other non-current assets	5,760	6,505
Total assets	565,697	385,505
Current liabilities
Other accounts payable		1
Accrued expenses	89,095	63,033
Other current liabilities		1
Total current liabilities	89,095	63,035
Long-term borrowings	898,778	898,514
Total liabilities	987,873	961,549
Commitments and contingencies
Stockholders' equity
Common stock	136,229	136,229
Additional paid-in capital	(731,240)	(733,223)
Retained earnings	212,140	35,760
Accumulated other comprehensive loss	(39,305)	(14,810)
Total stockholders' equity	(422,176)	(576,044)
Total liabilities and stockholders' equity	565,697	385,505
Non-Guarantors [Member]
Current assets
Cash and cash equivalents	168,176	127,118	112,370	45,443
Restricted cash	133	6,830
Accounts receivable, net	143,514	126,391
Inventories, net	89,363	62,836
Other receivables	3,288	7,581
Prepaid expenses	10,544	8,509
Current deferred income tax assets	20,177
Other current assets	8,918	11,738
Total current assets	444,113	351,003
Property, plant and equipment, net	238,157	182,583
Intangible assets, net	15,138	16,514
Long-term prepaid expenses	21,382	10,963
Deferred income tax assets	44,927
Other non-current assets	8,818	8,170
Total assets	772,535	569,233
Current liabilities
Accounts payable	101,877	99,560
Other accounts payable	15,490	13,115
Accrued expenses	235,921	186,678
Current portion of capital lease obligations		2,852
Other current liabilities	3,507	11,544
Total current liabilities	356,795	313,749
Long-term borrowings	606,000	642,383
Accrued severance benefits, net	112,210	90,611
Other non-current liabilities	15,071	3,894
Total liabilities	1,090,076	1,050,637
Commitments and contingencies
Stockholders' equity
Common stock	39,005	39,005
Additional paid-in capital	(534,819)	(536,894)
Retained earnings	217,341	35,141
Accumulated other comprehensive loss	(39,068)	(18,656)
Total stockholders' equity	(317,541)	(481,404)
Total liabilities and stockholders' equity	772,535	569,233
Guarantors [Member]
Current assets
Cash and cash equivalents	1,330	8,197	13,128	19,322
Accounts receivable, net	23,143	22,179
Inventories, net		158
Other receivables	183	399
Prepaid expenses	201	384
Current deferred income tax assets	2,591
Other current assets	199,034	183,685
Total current assets	226,482	215,002
Property, plant and equipment, net	99	80
Intangible assets, net	122	273
Long-term prepaid expenses		66
Deferred income tax assets	1,783
Investment in subsidiaries	(317,612)	(481,478)
Long-term intercompany loan	621,992	660,066
Other non-current assets	288	3,864
Total assets	533,154	397,873
Current liabilities
Accounts payable	360	842
Other accounts payable	679	6,195
Accrued expenses	244,467	207,770
Other current liabilities	3,131	3,117
Total current liabilities	248,637	217,924
Long-term borrowings	792,361	827,596
Accrued severance benefits, net	236	144
Other non-current liabilities	5,525	8,567
Total liabilities	1,046,759	1,054,231
Commitments and contingencies
Stockholders' equity
Common stock	51,976	51,976
Additional paid-in capital	(729,213)	(731,209)
Retained earnings	203,133	37,722
Accumulated other comprehensive loss	(39,501)	(14,847)
Total stockholders' equity	(513,605)	(656,358)
Total liabilities and stockholders' equity	533,154	397,873
Eliminations [Member]
Current assets
Accounts receivable, net	(23,326)	(22,648)
Inventories, net		(158)
Other receivables	(44,681)	(19,518)
Prepaid expenses	(2,897)	(2,897)
Other current assets	(526,306)	(426,168)
Total current assets	(597,210)	(471,389)
Long-term prepaid expenses	(3,334)	(6,239)
Investment in subsidiaries	1,253,323	1,713,965
Long-term intercompany loan	(2,095,486)	(2,167,104)
Total assets	(1,442,707)	(930,767)
Current liabilities
Accounts payable	(23,001)	(22,554)
Other accounts payable	(45,007)	(19,518)
Accrued expenses	(526,305)	(426,260)
Other current liabilities	(2,897)	(2,898)
Total current liabilities	(597,210)	(471,230)
Long-term borrowings	(2,095,486)	(2,167,104)
Other non-current liabilities	(3,333)	(6,239)
Total liabilities	(2,696,029)	(2,644,573)
Commitments and contingencies
Stockholders' equity
Common stock	(227,210)	(227,210)
Additional paid-in capital	1,995,272	2,001,326
Retained earnings	(632,614)	(108,623)
Accumulated other comprehensive loss	117,874	48,313
Total stockholders' equity	1,253,322	1,713,806
Total liabilities and stockholders' equity	(1,442,707)	(930,767)
Consolidated [Member]
Current assets
Cash and cash equivalents	182,238	162,111	172,172	64,925
Restricted cash	133	6,830
Accounts receivable, net	143,331	125,922
Inventories, net	89,363	62,836
Other receivables	1,429	256
Prepaid expenses	7,884	6,032
Current deferred income tax assets	22,768
Other current assets	9,680	15,909
Total current assets	456,826	379,896
Property, plant and equipment, net	238,256	182,663
Intangible assets, net	15,260	16,787
Long-term prepaid expenses	18,048	4,790
Deferred income tax assets	46,710
Other non-current assets	14,866	18,539
Total assets	789,966	602,675
Current liabilities
Accounts payable	79,236	77,848
Other accounts payable	15,600	13,452
Accrued expenses	43,486	31,723
Current portion of capital lease obligations		2,852
Other current liabilities	9,973	11,764
Total current liabilities	148,295	137,639
Long-term borrowings	201,653	201,389
Accrued severance benefits, net	112,446	90,755
Other non-current liabilities	17,263	6,222
Total liabilities	479,657	436,005
Commitments and contingencies
Stockholders' equity
Common stock	396	394
Additional paid-in capital	101,885	98,929
Retained earnings	287,251	93,950
Treasury stock	(39,918)	(11,793)
Accumulated other comprehensive loss	(39,305)	(14,810)
Total stockholders' equity	310,309	166,670
Total liabilities and stockholders' equity	$ 789,966	$ 602,675