Consolidation - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets
Cash equivalents	$ 147,135	$ 197,240
Total assets measured at fair value	247,396	307,226
Liabilities
Total liabilities measured at fair value	38,408	56,200
Level 1
Assets
Cash equivalents	147,135	197,240
Total assets measured at fair value	247,396	307,226
Liabilities
Total liabilities measured at fair value	0	0
Level 2
Assets
Cash equivalents	0	0
Total assets measured at fair value	0	0
Liabilities
Total liabilities measured at fair value	0	0
Level 3
Assets
Cash equivalents	0	0
Total assets measured at fair value	0	0
Liabilities
Total liabilities measured at fair value	38,408	56,200
Fair Value, Measurements, Recurring | Consolidated Investment Products
Assets
Cash equivalents	163,605	98,101
Derivatives	124
Total assets measured at fair value	2,270,388	2,180,814
Liabilities
Notes payable	1,990,338	1,922,243
Short sales	474	518
Total liabilities measured at fair value	1,990,812	1,922,761
Fair Value, Measurements, Recurring | Debt investments | Consolidated Investment Products
Assets
Investments	2,069,459	2,049,617
Fair Value, Measurements, Recurring | Equity investments | Consolidated Investment Products
Assets
Investments	37,200	33,096
Fair Value, Measurements, Recurring | Level 1 | Consolidated Investment Products
Assets
Cash equivalents	163,605	98,101
Derivatives	124
Total assets measured at fair value	198,958	130,984
Liabilities
Notes payable	0	0
Short sales	474	518
Total liabilities measured at fair value	474	518
Fair Value, Measurements, Recurring | Level 1 | Debt investments | Consolidated Investment Products
Assets
Investments	0	241
Fair Value, Measurements, Recurring | Level 1 | Equity investments | Consolidated Investment Products
Assets
Investments	35,229	32,642
Fair Value, Measurements, Recurring | Level 2 | Consolidated Investment Products
Assets
Cash equivalents	0	0
Derivatives	0
Total assets measured at fair value	2,034,447	2,012,768
Liabilities
Notes payable	1,990,338	1,922,243
Short sales	0	0
Total liabilities measured at fair value	1,990,338	1,922,243
Fair Value, Measurements, Recurring | Level 2 | Debt investments | Consolidated Investment Products
Assets
Investments	2,034,350	2,012,760
Fair Value, Measurements, Recurring | Level 2 | Equity investments | Consolidated Investment Products
Assets
Investments	97	8
Fair Value, Measurements, Recurring | Level 3 | Consolidated Investment Products
Assets
Cash equivalents	0	0
Derivatives	0
Total assets measured at fair value	36,983	37,062
Liabilities
Notes payable	0	0
Short sales	0	0
Total liabilities measured at fair value	0	0
Fair Value, Measurements, Recurring | Level 3 | Debt investments | Consolidated Investment Products
Assets
Investments	35,109	36,616
Fair Value, Measurements, Recurring | Level 3 | Equity investments | Consolidated Investment Products
Assets
Investments	$ 1,874	$ 446