Carrying Amounts of Amortizable Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross cost	$ 21,630	[1]	$ 12,968
Accumulated amortization	(7,578)	[2]	(5,908)	[2]
Net	14,052		7,060
Trade Name
Finite-Lived Intangible Assets [Line Items]
Gross cost	6,006	[1]	5,758
Accumulated amortization	(2,890)	[2]	(2,303)	[2]
Net	3,116		3,455
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross cost	10,468	[1]	7,210
Accumulated amortization	(4,569)	[2]	(3,605)	[2]
Net	5,899		3,605
content
Finite-Lived Intangible Assets [Line Items]
Gross cost	3,269	[1]
Accumulated amortization	(68)	[2]
Net	3,201
Software
Finite-Lived Intangible Assets [Line Items]
Gross cost	1,887	[1]
Accumulated amortization	(51)	[2]
Net	$ 1,836

[1] The Company acquired Ideas International in the second quarter of 2012 and recorded $8.4 million of amortizable intangible assets, allocated as follows: Trade Name-$0.2 million; Customer Relationships-$3.2 million; Content-$3.2 million; and Software-$1.8 million.

[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.