Acquisitions - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	12 Months Ended				1 Months Ended	12 Months Ended			12 Months Ended				1 Months Ended	12 Months Ended				1 Months Ended
	May 23, 2012 Thoughtcorp Inc	Dec. 31, 2012 Thoughtcorp Inc	Dec. 31, 2012 Thoughtcorp Inc Trade Name	Dec. 31, 2012 Thoughtcorp Inc Sales, general and administrative Stock Based Compensation Expense and Bonuses	Dec. 31, 2012 Thoughtcorp Inc Sales, general and administrative Professional Fees	May 23, 2012 Thoughtcorp Inc Restricted Stock Units (RSUs)	Dec. 31, 2010 Instant Information Inc	Aug. 20, 2010 Instant Information Inc	Dec. 31, 2011 Instant Information Inc	Aug. 20, 2010 Instant Information Inc Trade Name	Dec. 31, 2012 Instant Information Inc IPO	Dec. 31, 2010 Instant Information Inc Sales, general and administrative Service Costs	Dec. 31, 2012 Instant Information Inc Sales, general and administrative IPO	Dec. 18, 2012 Empathy Lab LLC	Dec. 31, 2012 Empathy Lab LLC	Dec. 31, 2012 Empathy Lab LLC Trade Name	Dec. 31, 2012 Empathy Lab LLC Sales, general and administrative Stock Based Compensation Expense and Bonuses	Dec. 31, 2012 Empathy Lab LLC Sales, general and administrative Professional Fees	Dec. 18, 2012 Empathy Lab LLC Non Vested Stock
Business Acquisition [Line Items]
Business acquisition, cash paid	$ 7,497							$ 360						$ 27,257
Shares placed in escrow period	18 months													18 months					18 months
Percentage of consideration placed in escrow														10.00%
Issuance of restricted common stock						217,272													326,344
Shares placed in escrow																			65,268
Issuance of restricted common stock, shares						3,607													6,755
Vesting period						2 years													3 years
Expected tax goodwill		8,310													11,470
Amortization period of goodwill for tax purposes								15 years							15 years
Revenue of acquiree included in consolidated statements of income		7,184					677								545
Net income (losses) of acquiree included in consolidated statements of income		206					(873)								104
Acquisition related costs				1,252	420							63					79	81
Business acquisition, common stock	217,274
Fair value of shares at the time of issuance	3,607
Percent of tax basis of acquired goodwill amortized at a rate of 7%		75.00%
Goodwill amortization rate		7.00%
Business acquisition, contingent consideration stock issuable								1,000
Initial public offering common stock issued											53,336
Stock issuance cost													640
Amortizable intangible assets								$ 216		$ 216
Amortization period of intangible assets			5 years							5 years						5 years