Consolidated Statements Of Changes In Redeemable Preferred Stock And Stockholders' Equity (USD $) In Thousands, except Share data	Total USD ($)	Initial Public Offering USD ($)	Instant Information Inc USD ($)	Thoughtcorp Inc USD ($)	Series A-1 convertible redeemable preferred stock USD ($)	Series A-2 convertible redeemable preferred stock USD ($)	Series A-1 and A-2, Convertible Redeemable Preferred Stock USD ($)	Series A-1 and A-2, Convertible Redeemable Preferred Stock Series A-1 convertible redeemable preferred stock USD ($)	Series A-1 and A-2, Convertible Redeemable Preferred Stock Series A-2 convertible redeemable preferred stock USD ($)	Common Stock USD ($)	Common Stock Initial Public Offering USD ($)	Common Stock Instant Information Inc	Common Stock Thoughtcorp Inc	Common Stock Empathy Lab LLC	Common Stock Puttable common stock USD ($)	Series A-3 Convertible Preferred Stock	Additional Paid-in Capital USD ($)	Additional Paid-in Capital Initial Public Offering USD ($)	Additional Paid-in Capital Instant Information Inc USD ($)	Additional Paid-in Capital Thoughtcorp Inc USD ($)	Additional Paid-in Capital Empathy Lab LLC USD ($)	Retained Earnings USD ($)	Retained Earnings Series A-1 convertible redeemable preferred stock USD ($)	Retained Earnings Series A-2 convertible redeemable preferred stock USD ($)	Treasury Stock USD ($)	Treasury Stock Thoughtcorp Inc USD ($)	Treasury Stock Empathy Lab LLC USD ($)	Accumulated Other Comprehensive Income USD ($)
Beginning Balance at Dec. 31, 2009	$ 16,534						$ 87,413			$ 17					$ 1,264		$ 12,582					$ 20,842			$ (15,040)			$ (1,867)
Beginning Balance (in shares) at Dec. 31, 2009							2,730,016			17,060,504					171,312
Accretion of preferred stock to redemption value					(1,432)			1,432															(1,432)
Stock issued	6,334																(58)								6,392
Repurchase and retirement of Series A-2 convertible redeemable preferred stock (in shares)							(290,277)
Repurchase and retirement of Series A-2 convertible redeemable preferred stock	5,418						(20,468)										5,418
Issue of Series A-3 convertible preferred stock (in shares)																290,277
Issue of Series A-3 convertible preferred stock	14,971																14,971
Purchase of common stock (Note 13)	(6,392)																								(6,392)
Purchase of puttable stock (in shares) (Note 13)															(114,416)
Purchase of puttable stock (Note 13)															(932)		932								(932)
Adjustment of shares issued in connection with acquisition of Rodmon (in shares)										(11,696)
Adjustment of shares issued in connection with acquisition of Rodmon	(60)																(60)
Stock-based compensation expense	2,939																2,939
Proceeds from stock options exercises (in shares)	5,600									5,600
Proceeds from stock options exercises	26																26
Currency translation adjustment	(397)																											(397)
Net income	28,308																					28,308
Ending Balance at Dec. 31, 2010	66,249						68,377			17					332		36,750					47,718			(15,972)			(2,264)
Ending Balance (in shares) at Dec. 31, 2010							2,439,739			17,054,408					56,896	290,277
Accretion of preferred stock to redemption value						(17,563)			17,563															(17,563)
Stock-based compensation expense	2,866																2,866
Proceeds from stock options exercises (in shares)	47,600									47,600
Proceeds from stock options exercises	72																72
Put option expiry (in shares)										56,896					(56,896)
Put option expiry	332														(332)		332
Currency translation adjustment	(1,250)																											(1,250)
Net income	44,353																					44,353
Ending Balance at Dec. 31, 2011	95,059						85,940			17							40,020					74,508			(15,972)			(3,514)
Ending Balance (in shares) at Dec. 31, 2011							2,439,739			17,158,904						290,277
Stock issued (in shares)											2,900,000
Stock issued		32,364									3							32,361
Conversion to common stock (in shares)	21,840,128						(2,439,739)			21,840,128						(290,277)
Conversion to common stock	85,940						(85,940)			22							85,918
Offering issuance costs	(3,395)																(3,395)
Issuance of restricted stock (Note 14)										213,656
Stock issued in connection with acquisition (in shares)												53,336	434,546	326,344
Stock issued in connection with acquisition			640	3,607															640	(346)	(2,969)					3,953	2,969
Stock-based compensation expense	6,826																6,826
Proceeds from stock options exercises (in shares)	1,552,742									1,515,580
Proceeds from stock options exercises	4,965									2							4,963
Treasury stock retirement																	(353)								353
Excess tax benefits	3,297																3,297
Currency translation adjustment	2,493																											2,493
Net income	54,484																					54,484
Ending Balance at Dec. 31, 2012	$ 286,280									$ 44							$ 166,962					$ 128,992			$ (8,697)			$ (1,021)
Ending Balance (in shares) at Dec. 31, 2012										44,442,494