Business and Significant Accounting Policies (Detail) - Intangible Assets Subject to Amortization (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
Gross cost		$ 12,968		$ 12,968
Additions due to acquisition (1)	8,500	8,535	[1]
Foreign currency translation impact		649
Gross cost		22,152		12,968
Accumulated amortization		(10,331)	[2]	(5,908)	[2]
Balance	11,821	7,060
Trade Names [Member]
Gross cost		5,758		5,758
Additions due to acquisition (1)		240	[1]
Foreign currency translation impact		21
Gross cost		6,019		5,758
Accumulated amortization		(3,531)	[2]	(2,303)	[2]
Balance	2,488	3,455
Customer Relationships [Member]
Gross cost		7,210		7,210
Additions due to acquisition (1)		3,170	[1]
Foreign currency translation impact		182
Gross cost		10,562		7,210
Accumulated amortization		(5,896)	[2]	(3,605)	[2]
Balance	4,666	3,605
Content [Member]
Additions due to acquisition (1)		3,170	[1]
Foreign currency translation impact		277
Gross cost		3,447
Accumulated amortization		(497)	[2]		[2]
Balance	2,950
Computer Software, Intangible Asset [Member]
Additions due to acquisition (1)		1,955	[1]
Foreign currency translation impact		169
Gross cost		2,124
Accumulated amortization		(407)	[2]		[2]
Balance	$ 1,717

[1] The Company acquired Ideas International in 2012 and recorded a total of $8.5 million of amortizable intangible assets. See Note 2-Acquisitions above for additional information.

[2] Intangible assets are being amortized against earnings over the following periods: Trade name-2 to 5 years; Customer relationships-4 years; Content-4 years; Software-3 years. Aggregate amortization expense related to intangible assets was $4.4 million, $6.5 million, and $10.5 million in 2012, 2011, and 2010, respectively.