Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill	$ 226,034,000	$ 226,189,000
Book value of assets per share (in dollars per share)		$ 8.25
Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Share price of common stock (in dollars per share)		$ 9.03
FolioDynamix
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill	166,200,000
Impairment loss	39,700,000
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	$ 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 | FolioDynamix | Goodwill
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate (as a percent)	23.40%