Discontinued Operations - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended	1 Months Ended	9 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013 Subsidiaries	Dec. 04, 2013 Procurian	Sep. 30, 2014 Procurian	Sep. 30, 2014 Procurian	Dec. 31, 2013 Procurian	Jan. 31, 2013 Investor Force	Sep. 30, 2014 Investor Force	Sep. 30, 2013 Investor Force	Feb. 20, 2013 Channel Intelligence	Sep. 30, 2014 Channel Intelligence	Sep. 30, 2013 Channel Intelligence
Subsidiary Or Equity Method Investee [Line Items]
Number of subsidiaries sold					3
Consideration from divestiture of business						$ 375,000,000				$ 23,600,000			$ 125,000,000
Consideration from sale of business in cash						327,800,000				20,800,000			60,500,000
Gain (Loss) on sale of business							(1,200,000)		224,900,000		2,100,000	15,700,000		5,800,000	17,800,000
Income (loss) from discontinued operations, including gain on sale, net of tax	2,426,000	4,980,000	3,789,000	35,654,000				100,000
Income tax benefit on loss from discontinued operations	$ 2,100,000	$ 3,000,000		$ 3,200,000