Goodwill and Intangible Assets - Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Customer relationships, Gross Carrying Amount	$ 57,319	$ 57,040
Non-compete agreements, Gross Carrying Amount	12,077	12,016
Gross Carrying Amount	160,803	160,060
Accumulated Amortization	(84,119)	(73,324)
Net Balance	76,684	86,736
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Net Balance, Indefinite-Lived Intangible Assets	35,801	35,537
Accumulated Amortization
Domain Names [Member]
Finite-Lived Intangible Assets [Line Items]
Net Balance, Indefinite-Lived Intangible Assets	4,400	4,400
Accumulated Amortization
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Weighted-Average Amortization Period	10 years
Accumulated Amortization	(42,482)	(36,464)
Net Balance, Finite-Lived Intangible Assets	14,837	20,576
Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Weighted-Average Amortization Period	12 years
Acquired technology, Gross Carrying Amount	51,206	51,067
Accumulated Amortization	(29,734)	(25,108)
Net Balance, Finite-Lived Intangible Assets	21,472	25,959
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Weighted-Average Amortization Period	4 years
Accumulated Amortization	(11,903)	(11,752)
Net Balance, Finite-Lived Intangible Assets	$ 174	$ 264