Adjusted funding target attainment percentage.

Name:	mas_AdjustedFundingTargetAttainmentPercentage
Namespace Prefix:	mas
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined benefit plan assumption used calculating adjusted funding target attainment maximum.

+ Details

Name:	mas_DefinedBenefitPlanAssumptionUsedCalculatingAdjustedFundingTargetAttainmentMaximum
Namespace Prefix:	mas
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined benefit plan assumption used calculating adjusted funding target attainment minimum.

+ Details

Name:	mas_DefinedBenefitPlanAssumptionUsedCalculatingAdjustedFundingTargetAttainmentMinimum
Namespace Prefix:	mas
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Employee retirement plans.

+ Details

Name:	mas_EmployeeRetirementPlansTextualsAbstract
Namespace Prefix:	mas
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of plan offered for accelerated benefit.

+ Details

Name:	mas_NumberOfPlanOfferedForAcceleratedBenefit
Namespace Prefix:	mas
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Prohibited percentage of lump sum distribution.

+ Details

Name:	mas_ProhibitedPercentageOfLumpSumDistribution
Namespace Prefix:	mas
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reduction in employee expenses related accruals.

+ Details

Name:	mas_ReductionInEmployeeExpensesRelatedAccruals
Namespace Prefix:	mas
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of gains or losses recognized in net periodic benefit cost

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

+ Details

Name:	us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

+ Details

Name:	us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 106

-Paragraph 518

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 87

-Paragraph 264

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

+ Details

Name:	us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

+ References

+ Details

Name:	us-gaap_DefinedBenefitPlanInterestCost
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain or loss, prior service cost or credit, transition asset or obligation, and gain or loss due to settlements or curtailments).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

+ Details

Name:	us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

+ References

+ Details

Name:	us-gaap_DefinedBenefitPlanServiceCost
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph c

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 6

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 3

+ Details

Name:	us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Employee Retirement Plans (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010 Plan	Sep. 30, 2011 Qualified [Member]	Sep. 30, 2010 Qualified [Member]	Sep. 30, 2011 Qualified [Member]	Sep. 30, 2010 Qualified [Member]	Sep. 30, 2011 Non-Qualified [Member]	Sep. 30, 2010 Non-Qualified [Member]	Sep. 30, 2011 Non-Qualified [Member]	Sep. 30, 2010 Non-Qualified [Member]	Dec. 31, 2010 Non-Qualified [Member]
Net periodic pension cost for defined-benefit pension plans
Service cost			$ 1	$ 2	$ 2	$ 4	$ 0	$ 0	$ 0	$ 0
Interest cost			12	11	34	34	2	3	6	7
Expected return on plan assets			(9)	(9)	(25)	(27)	0	0	0	0
Amortization of prior service cost			0	0	0	0	0	0	0	0
Amortization of net loss			2	3	7	8	1	0	1	0
Net periodic pension cost			6	7	18	19	3	3	7	7
Net Liability of defined-benefit pension plans		522									163
Employee Retirement Plans (Textuals) [Abstract]
Minimum adjusted funding target attainment percentage of defined-benefit pension plans		62.00%
Maximum adjusted funding target attainment percentage of defined-benefit pension plans		86.00%
Number of plan offered for accelerated benefit		1
Adjusted Funding Target Attainment Percentage		less than 80 percent
Prohibited percentage of lump sum distribution		excess of 50 percent
Reduction in employee expenses related accruals	$ 5