XML 141 R105.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Stock-Based Compensation - Summary of Stock-Based Compensation Expense Recorded in Selling, General and Administrative Expenses (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Incentive Stock Option Plan [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total stock-based compensation expense | $ 40 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_IncentiveStockOptionPlanMember | $ 40 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_IncentiveStockOptionPlanMember | $ 42 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_IncentiveStockOptionPlanMember
Selling, General and Administrative Expenses [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total stock-based compensation expense | 40 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember | 35 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember | 38 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember
Selling, General and Administrative Expenses [Member] | Incentive Stock Option Plan [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total stock-based compensation expense | 15 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_IncentiveStockOptionPlanMember | 15 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_IncentiveStockOptionPlanMember | 19 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_IncentiveStockOptionPlanMember
Selling, General and Administrative Expenses [Member] | Long-term Retention [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total stock-based compensation expense | 4 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_LongTermRetentionPlanMember | 4 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_LongTermRetentionPlanMember | 5 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_LongTermRetentionPlanMember
Selling, General and Administrative Expenses [Member] | Restricted Stock Unit [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total stock-based compensation expense | 21 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_RestrictedStockUnitMember | 16 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_RestrictedStockUnitMember | 14 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_RestrictedStockUnitMember
Selling, General and Administrative Expenses [Member] | Fair Value Adjustment for Liability Classified DSUs [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total stock-based compensation expense |  | $ 5 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_FairValueAdjustmentMember | $ 4 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingGeneralAndAdministrativeExpensesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = mga_FairValueAdjustmentMember

X
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section F + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_SellingGeneralAndAdministrativeExpensesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=mga_IncentiveStockOptionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |