Contingency under Credit Agreement, Availability Threshold, Percent

No definition available.

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Namespace Prefix:	mat_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contingency under Credit Agreement, Excess Availability under Credit Facility

+ References

No definition available.

+ Details

Name:	mat_ContingencyunderCreditAgreementExcessAvailabilityunderCreditFacility
Namespace Prefix:	mat_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fixed Charge Coverage Ratio for Covenant Compliance

+ References

No definition available.

+ Details

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Namespace Prefix:	mat_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mat_CreditAgreementMember
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Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
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- Details

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- Details

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- Details

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- Details

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Seasonal Financing (Details)		1 Months Ended	9 Months Ended
Seasonal Financing (Details)	Dec. 20, 2017 USD ($) trading_day	Oct. 21, 2020 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)
Debt Instrument [Line Items]
Short-term borrowings			$ 400,000,000	$ 0	$ 230,000,000
Subsequent Event
Debt Instrument [Line Items]
Short-term borrowings		$ 76,300,000
Repayments of short-term borrowings		$ 323,700,000
Credit Agreement
Debt Instrument [Line Items]
Outstanding letters of credit			13,000,000	$ 55,000,000	$ 65,000,000
Revolving Credit Facility \| Credit Agreement
Debt Instrument [Line Items]
Aggregate commitment under the credit facility			1,600,000,000
Interest coverage ratio minimum for covenant compliance	1.00
Excess availability under credit facility	$ 100,000,000		$ 100,000,000
Availability threshold (as a percent)	10.00%
Threshold consecutive trading days \| trading_day	30
Revolving Credit Facility \| Credit Agreement \| Minimum \| LIBOR
Debt Instrument [Line Items]
Interest rate margin for loans (as a percent)			1.25%
Revolving Credit Facility \| Credit Agreement \| Minimum \| Base Rate
Debt Instrument [Line Items]
Interest rate margin for loans (as a percent)			0.25%
Revolving Credit Facility \| Credit Agreement \| Maximum \| LIBOR
Debt Instrument [Line Items]
Interest rate margin for loans (as a percent)			2.75%
Revolving Credit Facility \| Credit Agreement \| Maximum \| Base Rate
Debt Instrument [Line Items]
Interest rate margin for loans (as a percent)			1.75%
Revolving Credit Facility, Asset Based \| Credit Agreement
Debt Instrument [Line Items]
Aggregate commitment under the credit facility			$ 1,310,000,000
Revolving Credit Facility, Secured \| Credit Agreement
Debt Instrument [Line Items]
Aggregate commitment under the credit facility			$ 294,000,000.0