Consolidated VIEs - Summary of Consolidated VIE Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
ASSETS
Cash and cash equivalents	$ 896,843	$ 1,231,593
Customers and other receivables	132,616	125,696
Investments	523,366	531,995
Other assets	357,759	257,199
Total Assets	5,312,118	5,639,581
Liabilities:
Deposits and other customer payables	1,230,920	1,246,200
Other liabilities	507,223	534,268
Total Liabilities	4,628,150	4,958,007
Consolidated VIEs [Member]
ASSETS
Cash and cash equivalents	3,876	3,826
Customers and other receivables	424	102
Investments	152,481	97,474
Other assets	472	245
Total Assets	157,253	101,647
Liabilities:
Deposits and other customer payables	236	62
Other liabilities	679	513
Total Liabilities	$ 915	$ 575