Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended				12 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Forward Contracts [Member] Contract	Dec. 31, 2013 Internally Developed Software [Member]	Jun. 30, 2013 Restatement Adjustment [Member]	Dec. 31, 2013 MF Global Inc [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Minimum [Member] Business Combinations [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2013 Maximum [Member] Business Combinations [Member]
Property, Plant and Equipment [Line Items]
Maximum maturity period for classification of investments as cash equivalents	3 months
Investments other-than-temporary losses	$ 0	$ 0	$ 0
Number of foreign currency contracts				1
Contractual maturities accounts receivable	less than one year
Allowance for doubtful accounts	133,000	75,000	1,100,000
Provision for bad debts	200,000	500,000	1,200,000				900,000
Percentage of allowance against outstanding receivables	100.00%
Write-offs and other charges against the allowance for doubtful accounts	100,000	1,400,000	200,000
Estimated useful lives of amortizable intangibles								3 years		7 years
Estimated life of intangible assets					3 years			3 years	5 years	15 years	10 years
Term for post-contract technical support	1 year
Contract loss provisions recorded	0	0	0
Term of agreement for revenue recognition	2 years
Employee compensation and benefit expense						2,900,000
Depreciation and amortization	14,123,000	6,758,000	5,206,000			1,300,000
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	$ 32,703,000	$ 18,009,000				$ 1,600,000