XML 50 R81.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Warranty - Schedule of Company's Warranty Accruals (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Guarantees [Abstract] |  |  |
Balance, beginning of year | $ 91 us-gaap_ProductWarrantyAccrual | $ 94 us-gaap_ProductWarrantyAccrual | $ 76 us-gaap_ProductWarrantyAccrual
Expense, net | 47 mga_ProductWarrantyIncomeExpenseNet | 40 mga_ProductWarrantyIncomeExpenseNet | 43 mga_ProductWarrantyIncomeExpenseNet
Settlements | (40)us-gaap_ProductWarrantyAccrualPayments | (46)us-gaap_ProductWarrantyAccrualPayments | (46)us-gaap_ProductWarrantyAccrualPayments
Acquisitions [note 6] |  | 1 us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition | 17 us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition
Foreign exchange and other | (10)us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease | 2 us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease | 4 us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease
Balance, end of year | $ 88 us-gaap_ProductWarrantyAccrual | $ 91 us-gaap_ProductWarrantyAccrual | $ 94 us-gaap_ProductWarrantyAccrual

X
- Definition Product warranty income expense net. + References No definition available. + Details
Name: | mga_ProductWarrantyIncomeExpenseNet
Namespace Prefix: | mga_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_GuaranteesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15(5)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph 5 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph ((c)(5)) -URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249 + Details
Name: | us-gaap_ProductWarrantyAccrual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total liability for standard and extended product warranties acquired in a business acquisition. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249 + Details
Name: | us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total Increase or Decrease in the standard and extended product warranty liability due to currency translation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249 + Details
Name: | us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents the aggregate decrease in the liability related to payments to satisfy claims for standard and extended product warranties. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph ((c)(2)) -URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249 + Details
Name: | us-gaap_ProductWarrantyAccrualPayments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration