Condensed Consolidating Financial Information - Condensed Consolidating Statements Of Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 221,872	$ 200,405	$ 601,508	$ 592,005
Cost of sales	145,432	140,284	412,295	409,228
Gross profit	76,440	60,121	189,213	182,777
Selling, general and administrative expenses	21,388	17,881	59,690	50,740
Research and development expenses	19,470	19,003	59,063	58,115
Restructuring and impairment charge		1,621		4,096
IPO incentive				12,146
Operating income (loss)	35,582	21,616	70,460	57,680
Other income (expense)	16,731	(75,833)	6,845	(53,454)
Income (loss) before income taxes, equity in earnings (loss) of related equity investment	52,313	(54,217)	77,305	4,226
Income tax expenses (benefits)	3,901	1,793	9,290	6,138
Income (loss) before equity in earnings (loss) of related investment	48,412	(56,010)	68,015	(1,912)
Net income (loss)	48,412	(56,010)	68,015	(1,912)
Comprehensive income	42,031	(30,190)	61,745	(5,639)
MagnaChip Semiconductor Corporation (Parent) [Member]
Condensed Financial Statements, Captions [Line Items]
Selling, general and administrative expenses	489	354	2,586	1,650
Operating income (loss)	(489)	(354)	(2,586)	(1,650)
Other income (expense)	8,100		19,315	1
Income (loss) before income taxes, equity in earnings (loss) of related equity investment	7,611	(354)	16,729	(1,649)
Income tax expenses (benefits)	1,918	(1,456)	3,531	(1,474)
Income (loss) before equity in earnings (loss) of related investment	5,693	1,102	13,198	(175)
Equity in earnings (loss) of related investment	42,719	(57,112)	54,817	(1,737)
Net income (loss)	48,412	(56,010)	68,015	(1,912)
Comprehensive income	42,031	(30,190)	61,745	(5,639)
Co-Issuers [Member]
Condensed Financial Statements, Captions [Line Items]
Selling, general and administrative expenses	65	24	118	610
Operating income (loss)	(65)	(24)	(118)	(610)
Other income (expense)	7,892	(3,774)	1,891	28,262
Income (loss) before income taxes, equity in earnings (loss) of related equity investment	7,827	(3,798)	1,773	27,652
Income tax expenses (benefits)			(170)
Income (loss) before equity in earnings (loss) of related investment	7,827	(3,798)	1,943	27,652
Equity in earnings (loss) of related investment	34,817	(53,031)	52,661	(29,153)
Net income (loss)	42,644	(56,829)	54,604	(1,501)
Comprehensive income	36,264	(31,009)	48,335	(5,228)
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	221,971	200,405	601,742	591,967
Cost of sales	145,431	140,291	412,292	409,250
Gross profit	76,540	60,114	189,450	182,717
Selling, general and administrative expenses	21,569	17,946	58,681	49,740
Research and development expenses	20,052	19,846	61,164	60,538
Restructuring and impairment charge		1,610		2,409
IPO incentive				11,355
Operating income (loss)	34,919	20,712	69,605	58,675
Other income (expense)	12,301	(82,121)	(8,061)	(71,531)
Income (loss) before income taxes, equity in earnings (loss) of related equity investment	47,220	(61,409)	61,544	(12,856)
Income tax expenses (benefits)	11	(661)	288	532
Income (loss) before equity in earnings (loss) of related investment	47,209	(60,748)	61,256	(13,388)
Net income (loss)	47,209	(60,748)	61,256	(13,388)
Comprehensive income	40,257	(35,889)	55,682	(17,926)
Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	5,166	6,692	14,781	19,439
Cost of sales	449	780	1,050	1,392
Gross profit	4,717	5,912	13,731	18,047
Selling, general and administrative expenses	3,031	3,144	9,171	9,731
Research and development expenses	469	1,470	1,001	4,561
Restructuring and impairment charge		11		1,687
IPO incentive				791
Operating income (loss)	1,217	1,287	3,559	1,277
Other income (expense)	(11,562)	10,062	(6,300)	(10,186)
Income (loss) before income taxes, equity in earnings (loss) of related equity investment	(10,345)	11,349	(2,741)	(8,909)
Income tax expenses (benefits)	1,972	3,910	5,641	7,080
Income (loss) before equity in earnings (loss) of related investment	(12,317)	7,439	(8,382)	(15,989)
Equity in earnings (loss) of related investment	47,209	(60,753)	61,255	(13,400)
Net income (loss)	34,892	(53,314)	52,873	(29,389)
Comprehensive income	28,507	(27,495)	46,459	(33,136)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales	(5,265)	(6,692)	(15,015)	(19,401)
Cost of sales	(448)	(787)	(1,047)	(1,414)
Gross profit	(4,817)	(5,905)	(13,968)	(17,987)
Selling, general and administrative expenses	(3,766)	(3,587)	(10,866)	(10,991)
Research and development expenses	(1,051)	(2,313)	(3,102)	(6,984)
Restructuring and impairment charge				(1)
Operating income (loss)		(5)		(12)
Income (loss) before income taxes, equity in earnings (loss) of related equity investment		(5)		(12)
Income (loss) before equity in earnings (loss) of related investment		(5)		(12)
Equity in earnings (loss) of related investment	(124,745)	170,896	(168,733)	44,290
Net income (loss)	(124,745)	170,891	(168,733)	44,278
Comprehensive income	$ (105,028)	$ 94,393	$ (150,476)	$ 56,290