Debt - TaxAct 2013 Credit Facility - Additional Information (Detail) - USD ($)			1 Months Ended		12 Months Ended
	Sep. 10, 2013	Aug. 30, 2013	Aug. 31, 2013	Apr. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Credit facility borrowed					$ 607,650,000	$ 253,190,000
Loss on debt extinguishment and modification expense		$ 1,593,000			398,000	0	$ 1,593,000
TaxACT 2012 credit facility [Member]
Debt Instrument [Line Items]
Credit facility borrowed								$ 100,000,000.0
Principal repayments			$ 64,500,000	$ 10,000,000				$ 25,500,000
Derivative maturity date	Sep. 10, 2013
TaxACT 2013 credit facility [Member]
Debt Instrument [Line Items]
Agreement date		Aug. 30, 2013
Credit facility borrowed		$ 71,400,000			0	51,940,000
Principal repayments					$ 51,900,000	$ 19,400,000