Name:	mas_DefinedBenefitPlanChangeinFairValueofPlanAssetsLevel3TableTextBlock
Namespace Prefix:	mas_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the weighted average asset allocation based on fair value.

No definition available.

Name:	mas_DefinedBenefitPlanWeightedAverageAssetAllocationsTableTextBlock
Namespace Prefix:	mas_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the fair value of each major category of plan assets of qualified defined-benefit pension plan assets and the level within the fair value hierarchy in which the fair value measurements fall.

No definition available.

Name:	mas_QualifiedDefinedBenefitPensionPlanAssetsAtFairValueTableTextBlock
Namespace Prefix:	mas_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of pre-tax expense related to retirement plans.

No definition available.

Name:	mas_ScheduleOfRetirementPlansTableTextBlock
Namespace Prefix:	mas_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of assumption used to determine benefit obligation and net periodic benefit cost of defined benefit plan. Includes, but is not limited to, discount rate, rate of compensation increase, expected long-term rate of return on plan assets and interest crediting rate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfAssumptionsUsedTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of benefit obligation and plan assets for defined benefit pension plan with projected benefit obligation in excess of plan assets.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Name:	us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of net funded status of pension plans and/or other employee benefit plans.

Name:	us-gaap_ScheduleOfNetFundedStatusTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the amounts related to pension plans and/or other employee benefit plans in accumulated other comprehensive income or loss that have not yet been recognized as components of net periodic benefit cost, such as the net gain (loss), net prior service cost or credit, and net transition asset or obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920