Acquisitions - Additional Information (Detail) - Citigroup's Alternative Investor Services [Member] - USD ($) $ in Millions		4 Months Ended	6 Months Ended
	Mar. 11, 2016	Jun. 30, 2016	Jun. 30, 2016
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction	$ 321.0
Business acquisition, effective date of acquisition	Mar. 11, 2016
Fair value of acquired accounts receivable	$ 1.7
Reported revenues from acquisition		$ 65.1
Completed Technology [Member]
Business Acquisition [Line Items]
Amortized period			4 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Amortized period			13 years