Long-term Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended	3 Months Ended
	Nov. 30, 2011 2011 Senior Notes Unsecured Senior Notes 2.50% Due November 1, 2016	Sep. 30, 2012 2011 Senior Notes Unsecured Senior Notes 2.50% Due November 1, 2016	Nov. 30, 2011 2011 Senior Notes Unsecured Senior Notes 5.45% Due November 1, 2041	Sep. 30, 2012 2011 Senior Notes Unsecured Senior Notes 5.45% Due November 1, 2041	Sep. 30, 2012 Medium-Term Notes	Dec. 31, 2011 Medium-Term Notes
Debt Disclosure [Line Items]
Principal of debt instrument	$ 300.0		$ 300.0
Debt instrument maturity date	Nov. 01, 2016	Nov. 01, 2016	Nov. 01, 2041	Nov. 01, 2041
Issuance date	2011-11		2011-11
Interest rate	2.50%		5.45%
Interest terms of Senior Notes	Interest on the 2011 Senior Notes is payable semi-annually on May 1 and November 1 of each year, which began May 1, 2012.		Interest on the 2011 Senior Notes is payable semi-annually on May 1 and November 1 of each year, which began May 1, 2012.
Redemption terms of 2011 Senior Notes	Mattel may redeem all or part of the 2.50% Senior Notes at any time or from time to time at its option, at a redemption price equal to the greater of (i) 100% of the principal amount of the notes being redeemed plus accrued and unpaid interest to but excluding the redemption date, and (ii) a "make-whole" amount based on the yield of a comparable US Treasury security plus 25 basis points.		Mattel may redeem all or part of the 5.45% Senior Notes at any time or from time to time at its option prior to May 1, 2041 (six months prior to the maturity date of the 5.45% Senior Notes), at a redemption price equal to the greater of (i) 100% of the principal amount of the notes being redeemed plus accrued and unpaid interest to but excluding the redemption date, and (ii) a “make-whole” amount based on the yield of a comparable US Treasury security plus 35 basis points. Mattel may redeem all or part of the 5.45% Senior Notes at any time or from time to time at its option on or after May 1, 2041 (six months prior to the maturity date for the 5.45% Senior Notes), at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus accrued and unpaid interest to but excluding the redemption date.
Redemption price option one	100.00%		100.00%
Redemption price option two	0.25%		0.35%
Repayment of Medium-term notes					$ 50.0	$ 10.0