Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 182,987	$ 182,238	$ 156,623	$ 162,111
Restricted cash	37	133
Accounts receivable, net	146,267	143,331
Inventories, net	83,910	89,363
Other receivables	3,662	1,429
Prepaid expenses	10,401	7,884
Current deferred income tax assets	22,870	22,768
Other current assets	5,322	9,680
Total current assets	455,456	456,826
Property, plant and equipment, net	255,144	238,256
Intangible assets, net	12,169	15,260
Long-term prepaid expenses	16,101	18,048
Deferred income tax assets	42,804	46,710
Other non-current assets	15,359	14,866
Total assets	797,033	789,966
Current liabilities
Accounts payable	79,425	79,236
Other accounts payable	29,975	15,600
Accrued expenses	49,268	43,486
Derivative liabilities	4,619
Other current liabilities	3,136	9,973
Total current liabilities	166,423	148,295
Long-term borrowings, net	201,727	201,653
Accrued severance benefits, net	111,806	112,446
Other non-current liabilities	13,897	17,263
Total liabilities	493,853	479,657
Stockholders' equity
Common stock	397	396
Additional paid-in capital	103,310	101,885
Retained earnings	279,846	287,251
Treasury stock	(45,918)	(39,918)
Accumulated other comprehensive loss	(34,455)	(39,305)	(21,469)	(14,810)
Total stockholders' equity	303,180	310,309	163,905	166,670
Total liabilities and stockholders' equity	797,033	789,966
MagnaChip Semiconductor Corporation (Parent) [Member]
Current assets
Cash and cash equivalents	771	2,193	319	1,677
Other receivables	323	363
Prepaid expenses	139	36
Other current assets	89,714	84,045
Total current assets	90,947	86,637
Investment in subsidiaries	(430,112)	(422,475)
Long-term intercompany loan	697,125	697,125
Total assets	357,960	361,287
Current liabilities
Other accounts payable	54,206	44,438
Accrued expenses	574	308
Other current liabilities		6,232
Total current liabilities	54,780	50,978
Total liabilities	54,780	50,978
Stockholders' equity
Common stock	397	396
Additional paid-in capital	103,310	101,885
Retained earnings	279,846	287,251
Treasury stock	(45,918)	(39,918)
Accumulated other comprehensive loss	(34,455)	(39,305)
Total stockholders' equity	303,180	310,309
Total liabilities and stockholders' equity	357,960	361,287
Co-Issuers [Member]
Current assets
Cash and cash equivalents	2,505	10,539	25,094	25,119
Other receivables	50,276	42,276
Other current assets	255,474	243,989
Total current assets	308,255	296,804
Investment in subsidiaries	(516,426)	(513,236)
Long-term intercompany loan	771,128	776,369
Other non-current assets	5,549	5,760
Total assets	568,506	565,967
Current liabilities
Other accounts payable	8
Accrued expenses	99,599	89,095
Total current liabilities	99,607	89,095
Long-term borrowings, net	898,852	898,778
Total liabilities	998,459	987,873
Stockholders' equity
Common stock	136,229	136,229
Additional paid-in capital	(730,824)	(731,240)
Retained earnings	199,097	212,140
Accumulated other comprehensive loss	(34,455)	(39,305)
Total stockholders' equity	(429,953)	(422,176)
Total liabilities and stockholders' equity	568,506	565,697
Non-Guarantors [Member]
Current assets
Cash and cash equivalents	176,834	168,176	128,726	127,118
Restricted cash	37	133
Accounts receivable, net	147,284	143,514
Inventories, net	83,910	89,363
Other receivables	6,823	3,288
Prepaid expenses	13,378	10,544
Current deferred income tax assets	20,579	20,177
Other current assets	5,418	8,918
Total current assets	454,263	444,113
Property, plant and equipment, net	255,056	238,157
Intangible assets, net	12,084	15,138
Long-term prepaid expenses	19,247	21,382
Deferred income tax assets	41,485	44,927
Other non-current assets	9,541	8,818
Total assets	791,676	772,535
Current liabilities
Accounts payable	100,569	101,877
Other accounts payable	29,034	15,490
Accrued expenses	245,843	235,921
Derivative liabilities	4,619
Other current liabilities	2,980	3,507
Total current liabilities	383,045	356,795
Long-term borrowings, net	606,000	606,000
Accrued severance benefits, net	111,557	112,210
Other non-current liabilities	11,835	15,071
Total liabilities	1,112,437	1,090,076
Stockholders' equity
Common stock	39,735	39,005
Additional paid-in capital	(534,460)	(534,819)
Retained earnings	204,039	217,341
Accumulated other comprehensive loss	(30,075)	(39,068)
Total stockholders' equity	(320,761)	(317,541)
Total liabilities and stockholders' equity	791,676	772,535
Guarantors [Member]
Current assets
Cash and cash equivalents	2,877	1,330	2,484	8,197
Accounts receivable, net	21,080	23,143
Other receivables	1,433	183
Prepaid expenses	364	201
Current deferred income tax assets	2,291	2,591
Other current assets	208,130	199,034
Total current assets	236,175	226,482
Property, plant and equipment, net	88	99
Intangible assets, net	85	122
Investment in subsidiaries	(321,345)	(317,612)
Long-term intercompany loan	620,570	621,992
Deferred income tax assets	1,319	1,783
Other non-current assets	269	288
Total assets	537,161	533,154
Current liabilities
Accounts payable	610	360
Other accounts payable	2,263	679
Accrued expenses	256,300	244,467
Other current liabilities	4,002	3,131
Total current liabilities	263,175	248,637
Long-term borrowings, net	785,698	792,361
Accrued severance benefits, net	249	236
Other non-current liabilities	5,207	5,525
Total liabilities	1,054,329	1,046,759
Stockholders' equity
Common stock	51,246	51,976
Additional paid-in capital	(728,738)	(729,213)
Retained earnings	194,977	203,133
Accumulated other comprehensive loss	(34,653)	(39,501)
Total stockholders' equity	(517,168)	(513,605)
Total liabilities and stockholders' equity	537,161	533,154
Eliminations [Member]
Current assets
Accounts receivable, net	(22,097)	(23,326)
Other receivables	(55,193)	(44,681)
Prepaid expenses	(3,480)	(2,897)
Other current assets	(553,414)	(526,306)
Total current assets	(634,184)	(597,210)
Long-term prepaid expenses	(3,146)	(3,334)
Investment in subsidiaries	1,267,883	1,253,323
Long-term intercompany loan	(2,088,823)	(2,095,486)
Total assets	(1,458,270)	(1,442,707)
Current liabilities
Accounts payable	(21,754)	(23,001)
Other accounts payable	(55,536)	(45,007)
Accrued expenses	(553,048)	(526,305)
Other current liabilities	(3,846)	(2,897)
Total current liabilities	(634,184)	(597,210)
Long-term borrowings, net	(2,088,823)	(2,095,486)
Other non-current liabilities	(3,145)	(3,333)
Total liabilities	(2,726,152)	(2,696,029)
Stockholders' equity
Common stock	(227,210)	(227,210)
Additional paid-in capital	1,994,022	1,995,272
Retained earnings	(598,113)	(632,614)
Accumulated other comprehensive loss	99,183	117,874
Total stockholders' equity	1,267,882	1,253,322
Total liabilities and stockholders' equity	(1,458,270)	(1,442,707)
Consolidated [Member]
Current assets
Cash and cash equivalents	182,987	182,238	156,623	162,111
Restricted cash	37	133
Accounts receivable, net	146,267	143,331
Inventories, net	83,910	89,363
Other receivables	3,662	1,429
Prepaid expenses	10,401	7,884
Current deferred income tax assets	22,870	22,768
Other current assets	5,322	9,680
Total current assets	455,456	456,826
Property, plant and equipment, net	255,144	238,256
Intangible assets, net	12,169	15,260
Long-term prepaid expenses	16,101	18,048
Deferred income tax assets	42,804	46,710
Other non-current assets	15,359	14,866
Total assets	797,033	789,966
Current liabilities
Accounts payable	79,425	79,236
Other accounts payable	29,975	15,600
Accrued expenses	49,268	43,486
Derivative liabilities	4,619
Other current liabilities	3,136	9,973
Total current liabilities	166,423	148,295
Long-term borrowings, net	201,727	201,653
Accrued severance benefits, net	111,806	112,446
Other non-current liabilities	13,897	17,263
Total liabilities	493,853	479,657
Stockholders' equity
Common stock	397	396
Additional paid-in capital	103,310	101,885
Retained earnings	279,846	287,251
Treasury stock	(45,918)	(39,918)
Accumulated other comprehensive loss	(34,455)	(39,305)
Total stockholders' equity	303,180	310,309
Total liabilities and stockholders' equity	$ 797,033	$ 789,966