Business Acquisitions - Additional Information (Detail) (USD $)	6 Months Ended			0 Months Ended	3 Months Ended	6 Months Ended	0 Months Ended	3 Months Ended	6 Months Ended		0 Months Ended	6 Months Ended			6 Months Ended	0 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended		0 Months Ended	1 Months Ended		0 Months Ended	3 Months Ended			6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Feb. 05, 2014 OnPoint Consulting, Inc. [Member]	Jun. 30, 2014 OnPoint Consulting, Inc. [Member]	Jun. 30, 2014 OnPoint Consulting, Inc. [Member]	Dec. 30, 2013 La Comunidad [Member]	Jun. 30, 2014 La Comunidad [Member]	Jun. 30, 2014 La Comunidad [Member]	Dec. 31, 2013 La Comunidad [Member]	Jan. 16, 2013 iThink [Member]	Jun. 30, 2014 iThink [Member]	Dec. 31, 2013 iThink [Member]	Sep. 30, 2013 iThink [Member]	Jun. 30, 2014 iThink [Member] Maximum [Member]	Dec. 27, 2012 (m) Phasize, LLC [Member]	Jul. 31, 2013 (m) Phasize, LLC [Member]	Jun. 30, 2014 (m) Phasize, LLC [Member]	Jun. 30, 2014 (m) Phasize, LLC [Member]	Dec. 31, 2013 (m) Phasize, LLC [Member]	Jun. 30, 2013 (m) Phasize, LLC [Member]	Nov. 01, 2012 Second Story Inc. [Member]	Nov. 01, 2012 Second Story Inc. [Member]	Jun. 30, 2014 Second Story Inc. [Member]	Sep. 06, 2011 D&D Holdings Limited [Member]	Jun. 30, 2014 D&D Holdings Limited [Member]	Mar. 31, 2013 D&D Holdings Limited [Member]	Jun. 30, 2012 D&D Holdings Limited [Member]	Jun. 30, 2014 D&D Holdings Limited [Member]
Business Acquisition [Line Items]
Date of acquisition				Feb. 05, 2014			Dec. 30, 2013				Jan. 16, 2013					Dec. 27, 2012						Nov. 01, 2012			Sep. 06, 2011
Percentage of outstanding shares acquired				100.00%			100.00%				81.00%					100.00%						100.00%	100.00%		100.00%
Purchase price of entity acquired				$ 12,800,000			$ 21,000,000				$ 6,800,000					$ 18,500,000							$ 9,900,000		$ 45,200,000
Payments to acquire businesses, net of cash acquired	12,812,000	4,993,000		12,500,000			9,700,000				4,900,000
Cash paid for acquisition																12,100,000							6,000,000		29,500,000
Purchase price placed in escrow agreement				800,000							2,000,000					2,500,000						900,000	900,000		9,800,000
Security for any claims under escrow agreement				300,000							1,500,000					1,200,000						500,000	500,000
Payments to acquire businesses, portion allocated to settling final working capital adjustments					300,000		300,000
Business acquisition purchase price allocation goodwill amount	152,706,000	131,267,000	149,142,000	1,700,000			13,900,000				6,300,000					11,800,000						6,500,000	6,500,000		24,000,000
Business acquisition purchase price allocation intangible assets amount				7,800,000			6,100,000				1,400,000					5,900,000						2,400,000	2,400,000		25,200,000
Business acquisition purchase price allocation net assets acquired				3,300,000			1,100,000																		(4,000,000)
Service revenues					6,100,000	10,400,000
Net loss					2,000,000	3,000,000
Consideration transferred, equity interests issued and issuable							2,000,000
Estimated fair value of contingent consideration							9,300,000	10,000,000	10,000,000	9,300,000	700,000	0				6,100,000		3,900,000	3,900,000						15,700,000	3,800,000			3,800,000
Payment for contingent consideration																		5,500,000
Consideration transferred, equity interests issuable							1,500,000
Consideration transferred, equity interests issued and issuable, fair value							1,000,000
Consideration transferred, equity interests issuable, held as security							1,000,000
Consideration transferred, equity interests issuable, working capital adjustments							500,000
Fair value of noncontrolling interest											1,200,000
Business acquisition purchase price allocation net assets acquired											(400,000)					800,000						1,000,000	1,000,000
Contingent consideration arrangements, range of outcomes, value, high							24,000,000																		21,900,000
Additional consideration												11,700,000							12,800,000	12,800,000
Acquisition of membership interests											81.00%		84.00%	81.00%		100.00%
Estimated fair value of stock-based awards																300,000
Business acquisition revenue target																					1,000,000
Final working capital adjustments																	300,000						400,000
Restricted stock consideration fair value																							2,100,000
Deferred stock consideration at fair value																						1,800,000	1,800,000	1,700,000
Escrow cash released to former shareholders																											4,800,000	4,700,000
Gain (loss) from remeasurement of contingent consideration								$ (200,000)	$ (400,000)						$ 100,000			$ 700,000	$ (2,000,000)							$ 300,000			$ 2,800,000