v2.4.0.6

Fair Value Measurements (Financial Assets And (Liabilities) Measured At Fair Value) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative foreign currency forward contracts (refer to Note 8)	$ 0
TOLI policies held by the Rabbi Trust	0
Deferred Compensation Plan obligations	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative foreign currency forward contracts (refer to Note 8)	(1,344)
TOLI policies held by the Rabbi Trust	4,229
Deferred Compensation Plan obligations	(3,791)
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative foreign currency forward contracts (refer to Note 8)	0
TOLI policies held by the Rabbi Trust	0
Deferred Compensation Plan obligations	$ 0

X

- Definition

The Deferred Compensation Plan obligations represent the underlying liabilities to participants in this Plan.

+ References

No definition available.

+ Details

Name:	ua_DeferredCompensationPlanObligationsFairValueDisclosure
Namespace Prefix:	ua_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The fair value of the TOLI held by a Rabbi Trust is based on the cash-surrender value of the life insurance policies, which are invested primarily in mutual funds and a separately managed fixed income fund.

+ References

No definition available.

+ Details

Name:	ua_TrustOwnedLifeInsurancePoliciesFairValueDisclosure
Namespace Prefix:	ua_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

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

X

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents contracts related to the exchange of different currencies, including foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into and existing as of the balance sheet date.

+ References

No definition available.

+ Details

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