Related Party Transactions -Summary of Related Party Transactions (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Related party assets      
Cash and cash equivalents $ 37,121 $ 51,491  
Receivables (investment management fees) 74,321 37,980  
Receivables (fund administration and distribution fees) 19,313 3,153  
Investments (available-for-sale securities, fair value) 771 601  
Investments (trading securities, fair value) 18,305 12,719  
Related party liabilities      
Accounts payable and accrued expenses (fund reimbursements) 88,932 19,743  
Other liabilities (promissory note) 4,363 1,759  
Related party revenue      
Total revenue 612,373 413,412 $ 409,629
Investment Management Fees      
Related party revenue      
Total revenue 466,802 352,683 343,811
Fund Administration and Distribution Fees      
Related party revenue      
Total revenue 145,571 60,729 65,818
VCH      
Related party assets      
Cash and cash equivalents 10,060    
Receivables (investment management fees) 47,872 19,612  
Receivables (fund administration and distribution fees) 19,313 3,153  
Investments (available-for-sale securities, fair value) 771 601  
Investments (trading securities, fair value) 17,914 12,343  
Total 95,930 35,709  
Related party liabilities      
Accounts payable and accrued expenses (fund reimbursements) 4,316 2,300  
Other liabilities (promissory note)   96  
Total 4,316 2,396  
Related party revenue      
Total revenue 517,378 322,267 320,136
Related party expense      
Distribution and other asset-based expenses (fund reimbursements)   12,902 11,896
General and administrative   135 1,203
Total   13,037 13,099
Related party other income (expense)      
Interest income (expense) and other income (expense) 2,693 (2,834) 589
Interest expense and other financing costs (promissory note) (1) (18) (39)
Total 2,692 (2,852) 550
VCH | Investment Management Fees      
Related party revenue      
Total revenue 371,807 261,538 254,318
VCH | Fund Administration and Distribution Fees      
Related party revenue      
Total revenue $ 145,571 $ 60,729 $ 65,818