| N-2 | 6 Months Ended |
| Jun. 30, 2024 shares |
| Cover [Abstract] | |
| Entity Central Index Key | 0000809559 |
| Amendment Flag | false |
| Document Type | N-CSRS |
| Entity Registrant Name | TCW Strategic Income Fund, Inc. |
| General Description of Registrant [Abstract] | |
| Investment Objectives and Practices [Text Block] | Investment objective: Investment strategy: non-U.S. mid- |
| Risk Factors [Table Text Block] | Market Risk: Liquidity Risk: securities, foreign securities, derivatives or other securities with substantial market and/or credit risk tend to have the greatest exposure to liquidity risk. Certain investments in private placements and Rule 144A securities may be considered illiquid investments. The Fund may invest in private placements and Rule 144A securities. Interest Rate Risk: Mortgage-Backed and Other Asset-Backed Securities Risk: Derivatives Risk: Credit Risk: MBS and ABS are characterized and classified in a variety of different ways. These classifications include a view of the securities’ cash flow structure (pass-through, sequential pay, prepayment-protected, interest only, principal only, etc.), the security of the claim on the underlying assets (senior, mezzanine and subordinated), as well as types of underlying collateral (prime conforming loans, prime non-conforming Alt-A degree of subjectivity: a particular loan might be categorized as “prime” by the underwriting standards of one mortgage issuer while another might classify the loan as “subprime.” In addition to other functions, the risk associated with an investment in a mortgage loan must take into account the nature of the collateral, the form and the level of credit enhancement, the vintage of the loan, the geography of the loan, the purpose of the loan (refinance versus purchase versus equity takeout), the borrower’s credit quality (e.g., FICO score), and whether the loan is a first trust deed or a second lien. Counterparty Risk: LIBOR Transition Risk: |
| Market Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Market Risk: |
| Liquidity Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Liquidity Risk: securities, foreign securities, derivatives or other securities with substantial market and/or credit risk tend to have the greatest exposure to liquidity risk. Certain investments in private placements and Rule 144A securities may be considered illiquid investments. The Fund may invest in private placements and Rule 144A securities. |
| Mortgage-Backed and Other Asset-Backed Securities Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Mortgage-Backed and Other Asset-Backed Securities Risk: |
| Derivatives Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Derivatives Risk: |
| Credit Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Credit Risk: MBS and ABS are characterized and classified in a variety of different ways. These classifications include a view of the securities’ cash flow structure (pass-through, sequential pay, prepayment-protected, interest only, principal only, etc.), the security of the claim on the underlying assets (senior, mezzanine and subordinated), as well as types of underlying collateral (prime conforming loans, prime non-conforming Alt-A degree of subjectivity: a particular loan might be categorized as “prime” by the underwriting standards of one mortgage issuer while another might classify the loan as “subprime.” In addition to other functions, the risk associated with an investment in a mortgage loan must take into account the nature of the collateral, the form and the level of credit enhancement, the vintage of the loan, the geography of the loan, the purpose of the loan (refinance versus purchase versus equity takeout), the borrower’s credit quality (e.g., FICO score), and whether the loan is a first trust deed or a second lien. |
| Counterparty Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Counterparty Risk: |
| LIBOR Transition Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | LIBOR Transition Risk: |
| Interest Rate Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Interest Rate Risk: |
| Common Shares [Member] | |
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | |
| Outstanding Security, Title [Text Block] | Common Stock |
| Outstanding Security, Authorized [Shares] | 75,000,000 |
| Outstanding Security, Held [Shares] | 47,785,440 |
