EXTERNAL INVESTMENT MANAGER - Schedule of Balance Sheet (Details) - USD ($) $ in Thousands |
Mar. 31, 2025 |
Dec. 31, 2024 |
Mar. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|---|---|
| Investment Company, Nonconsolidated Subsidiary [Line Items] | ||||
| Total assets | $ 5,273,385 | $ 5,121,341 | ||
| Dividend payable to MSCC and its subsidiaries | 22,165 | 22,100 | ||
| Equity | 2,840,133 | 2,797,838 | $ 2,515,970 | $ 2,477,399 |
| Total liabilities and net assets | 5,273,385 | 5,121,341 | ||
| External Investment Manager | ||||
| Investment Company, Nonconsolidated Subsidiary [Line Items] | ||||
| Accounts receivable - advisory clients | 9,174 | 10,183 | ||
| Intangible Asset | 29,500 | 29,500 | ||
| Total assets | 38,674 | 39,683 | ||
| Accounts payable to MSCC and its subsidiaries | 6,681 | 7,785 | ||
| Dividend payable to MSCC and its subsidiaries | 2,493 | 2,398 | ||
| Equity | 29,500 | 29,500 | ||
| Total liabilities and net assets | $ 38,674 | $ 39,683 |
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of asset recognized for present right to economic benefit. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|