Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Jun. 30, 2013 Restatement Adjustment [Member]	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Minimum [Member] Business Combinations [Member]	Sep. 30, 2014 Maximum [Member]	Sep. 30, 2014 Maximum [Member] Business Combinations [Member]	Sep. 30, 2014 Internally Developed Software [Member]	Sep. 30, 2014 Forward Contracts [Member] Contract
Significant Accounting Policies [Line Items]
Maximum maturity period for classification of investments as cash equivalents			3 months
Investments other-than-temporary losses			$ 0	$ 0
Number of foreign currency contracts												1
Contractual maturities accounts receivable			less than one year
Term for post-contract technical support			1 year
Term of agreement for revenue recognition			2 years
Estimated life of intangible assets								3 years		15 years	3 years
Estimated useful life of fixed assets							3 years		7 years
Employee compensation and benefits expense	(18,589,000)	(17,910,000)	(55,619,000)	(47,638,000)		2,900,000
Depreciation and amortization	4,482,000	3,460,000	12,954,000	10,151,000		1,300,000
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	32,800,000		32,800,000		32,703,000	1,600,000
Reclassification from deferred tax assets to income and other liability					$ 2,300,000