Acquisitions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 VS [Member]	Jan. 30, 2014 VS [Member]	Mar. 31, 2014 VS [Member] Customer Contracts And Proprietary Software [Member]
Business Acquisition [Line Items]
Date of acquisition			Jan. 30, 2014
Operating assets acquired in cash	$ 7,312		$ 5,580
Fees incurred from third parties as part of acquisition			500
Business combinations revenue during period from acquired business			1,800
Business combinations net income during period from acquired business	5,238	2,871	(450)
Intangible assets subject to amortization				$ 75	$ 75
Weighted average life of intangible assets subject to amortization			10 years
Goodwill and intangible assets remaining amortized period			15 years