Goodwill and Intangible Assets, Net - Components of Intangible Assets with Definite Lives (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	6 years 9 months 18 days
Gross Carrying Amount	$ 37,790	$ 21,382
Accumulated Amortization	(15,968)	(13,492)
Intangible assets with definite lives, net	21,822	7,890
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	8 years 1 month 6 days
Gross Carrying Amount	21,217	14,431
Accumulated Amortization	(10,384)	(9,029)
Intangible assets with definite lives, net	10,833	5,402
Subscriber Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	6 years 3 months 18 days
Gross Carrying Amount	13,311	5,617
Accumulated Amortization	(4,270)	(3,511)
Intangible assets with definite lives, net	9,041	2,106
Technology Based and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	2 years 7 months 6 days
Gross Carrying Amount	3,262	1,334
Accumulated Amortization	(1,314)	(952)
Intangible assets with definite lives, net	$ 1,948	$ 382