Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Significant Accounting Policies [Line Items]
Royalty income under licensing agreements	$ 9,130	$ 7,073	$ 6,219
Advertising expenses	53,707	65,068	53,051
Research and development expenses	30,937	29,542	34,309
Foreign currency transaction gains (loss), net	(821)	(3,343)	708
Foreign currency translation adjustments	(2,593)	699	507
Percentage of net sales from regions outside United States	52.00%	53.00%	53.00%
Percentage of revenues	no single customer in the United States represented over 10% of the Company’s outstanding accounts receivable balance.	No single customer in the United States represented over 10% of the Company’s outstanding accounts receivable balance.
Gift Cards
Significant Accounting Policies [Line Items]
Deferred revenue	999	1,141
Unused Course Credits
Significant Accounting Policies [Line Items]
Deferred revenue	$ 1,807	$ 2,544

The aggregate foreign currency transaction gain (loss) (both realized and unrealized) included in determining net income for the reporting period. Excludes foreign currency transactions designated as hedges of net investment in a foreign entity and intercompany foreign currency transactions that are of a long-term nature, when the entities to the transaction are consolidated, combined, or accounted for by the equity method in the reporting enterprise's financial statements. For certain enterprises, primarily banks, that are dealers in foreign exchange, foreign currency transaction gains (losses) may be disclosed as dealer gains (losses).

+ References+ Details

Net of tax and reclassification adjustments of the change in the balance sheet adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency of the reporting entity. Also includes the following: gain (loss) on foreign currency forward exchange contracts; foreign currency transactions designated as hedges of net investment in a foreign entity and intercompany foreign currency transactions that are of a long-term nature, when the entities to the transaction are consolidated, combined, or accounted for by the equity method in the reporting enterprise's financial statements; and gain (loss) on a derivative instrument or nonderivative financial instrument that may give rise to a foreign currency transaction gain (loss) that has been designated and qualified as a hedging instrument for hedging of the foreign currency exposure of a net investment in a foreign operation.

+ References+ Details

- Definition

The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

+ References+ Details