AdvisorEngine - Financial Interests carrying value of the Company's financial interests (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Total net carrying value	$ 8,500	$ 36,284
Advisor Engine [Member]
Unsecured convertible note, Amortized Cost plus Accrued Interest	2,126	2,126
Unsecured non-convertible note, Amortized Cost, plus Accrued Interest	31,184	31,184
Preferred stock, Amortized Cost, plus Accrued Interest	25,000	25,000
Total amortized cost, plus accrued interest	58,310	58,310
Total net carrying value	8,500	28,172
Unsecured convertible note, Net Carrying Value		2,126
Unsecured non-convertible note, Net Carrying Value	$ 8,500	$ 26,046