Leases - Additional Information (Detail)	3 Months Ended
Mar. 31, 2022
Maximum [Member]
Lease Agreements Remaining Term of Lease	4 years
Minimum [Member]
Lease Agreements Remaining Term of Lease	1 year

Lease agreements remaining lease term for finance and operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	mx_RemainingLeaseTerm
Namespace Prefix:	mx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration