Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill	$ 226,034,000	$ 226,034,000
Book value of assets per share		$ 8.53
Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Share price of common stock		$ 9.05
FolioDynamix
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill	166,200,000
Impairment loss	39,700,000
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability		$ 0
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability		2,000,000.0
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability		$ 1,200,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | FolioDynamix
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill (annual impairment assessment)	$ 126,500,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | Goodwill | FolioDynamix
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate (as a percent)	23.40%