Fair Value Measurements (Details) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents | $ 38,980 | $ 36,971 |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 10,151 | 5,273 |
Net Asset Value [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure | 10,151 | 5,273 |
Cash equivalents | 0 | 0 |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 10,151 | 5,273 |
Consolidated Variable Interest Entities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure | 164,042 | 446,609 |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 114,911 | 404,365 |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 384,901 |
Consolidated Variable Interest Entities [Member] | Warehouse [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 50,752 | |
Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | | |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 0 | 0 |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 0 |
Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | Warehouse [Member] | | |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 0 | |
Consolidated Variable Interest Entities [Member] | Notes Payable of Consolidated CLOs [Member] | | |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 384,901 |
Consolidated Variable Interest Entities [Member] | Notes Payable of Consolidated CLOs [Member] | Net Asset Value [Member] | | |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 0 |
Collateralized Loan Obligations [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 5,150 | 272 |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 15,036 |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Senior Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 34,588 | |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Mezzanine Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 24,695 | |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Subordinated Debt [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 4,876 | |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 0 |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | Senior Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | Mezzanine Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | Subordinated Debt [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
First lien, senior secured loans [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 389,329 |
First lien, senior secured loans [Member] | Consolidated Variable Interest Entities [Member] | Net Asset Value [Member] | | |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | | 0 |
Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure | 38,980 | 36,971 |
Cash equivalents | 38,980 | 36,971 |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 0 | 0 |
Fair Value, Inputs, Level 1 [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | 0 |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 1 [Member] | Consolidated Variable Interest Entities [Member] | Warehouse [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 1 [Member] | Consolidated Variable Interest Entities [Member] | Notes Payable of Consolidated CLOs [Member] | | |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 1 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 1 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Senior Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 1 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Mezzanine Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 1 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Subordinated Debt [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 1 [Member] | First lien, senior secured loans [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure | 0 | 0 |
Cash equivalents | 0 | 0 |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 0 | 0 |
Fair Value, Inputs, Level 2 [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | 0 |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 2 [Member] | Consolidated Variable Interest Entities [Member] | Warehouse [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 2 [Member] | Consolidated Variable Interest Entities [Member] | Notes Payable of Consolidated CLOs [Member] | | |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 2 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 2 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Senior Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 2 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Mezzanine Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 2 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Subordinated Debt [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 0 | |
Fair Value, Inputs, Level 2 [Member] | First lien, senior secured loans [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 0 |
Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure | 114,911 | 404,365 |
Cash equivalents | 0 | 0 |
Investments, at fair value: | | |
Investments in affiliates, at net asset value | 0 | 0 |
Fair Value, Inputs, Level 3 [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 114,911 | 404,365 |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 384,901 |
Fair Value, Inputs, Level 3 [Member] | Consolidated Variable Interest Entities [Member] | Warehouse [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 50,752 | |
Fair Value, Inputs, Level 3 [Member] | Consolidated Variable Interest Entities [Member] | Notes Payable of Consolidated CLOs [Member] | | |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 384,901 |
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | 15,036 |
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Senior Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 34,588 | |
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Mezzanine Notes [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | 24,695 | |
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Subordinated Debt [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | $ 4,876 | |
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations [Member] | Consolidated Variable Interest Entities [Member] | Notes Payable of Consolidated CLOs [Member] | | |
Liabilities, at fair value: | | |
Liabilities Fair Value Disclosure | | 384,901 |
Fair Value, Inputs, Level 3 [Member] | First lien, senior secured loans [Member] | Consolidated Variable Interest Entities [Member] | | |
Investments, at fair value: | | |
Investments, Fair Value Disclosure | | $ 389,329 |