Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Significant Accounting Policies [Line Items]
Percentage of direct or indirect voting interest owned	more than 50%
Maintenance and customer support fees, contract life	1 year
Value of shares of common stock remaining in escrow	$ 0.3
Expiry period of contingent gains associated with outstanding escrows	2 years
Msdsonline One
Significant Accounting Policies [Line Items]
Number of sources of revenues	2
Minimum
Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage	20.00%
Maximum
Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage	50.00%
Channel Intelligence
Significant Accounting Policies [Line Items]
Proceeds from escrow releases	$ 28.8
Zurich | Consolidated Revenue
Significant Accounting Policies [Line Items]
Percentage of consolidated revenue	10.00%	10.00%