Amortization of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 1,024	$ 779	$ 999
Client relationships
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	627	720	871
Trade Name
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	333	59	19
Noncompete Agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	64
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets			$ 109