v3.26.3
Fair Value Measurements - Summary of Carrying Value and Fair Value of Debt Obligations (Parenthetical) (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Fair Value Disclosures [Abstract]
Secured Borrowings
$ 10,460
$ 12,000
X
- Definition
Secured borrowings.
+ References
No definition available.
+ Details
Name:
fdus_SecuredBorrowings
Namespace Prefix:
fdus_
Data Type:
xbrli:monetaryItemType
Balance Type:
credit
Period Type:
instant
X
- References
No definition available.
+ Details
Name:
us-gaap_FairValueDisclosuresAbstract
Namespace Prefix:
us-gaap_
Data Type:
xbrli:stringItemType
Balance Type:
na
Period Type:
duration