Leases - Schedule of Future Minimum Lease Payments Under Non-Cancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Leases [Abstract]
2024	$ 3,363
2025	2,797
2026	822
2027	604
2028	409
Thereafter	626
Total	$ 8,621

No definition available.

Lessee, Noncancelable Operating Lease, Liability, to be Paid

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaid
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Lessee, Noncancelable Operating Lease, Liability, to be Paid, After Year Five

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaidAfterYearFive
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Lessee, Noncancelable Operating Lease, Liability, to be Paid, Year Five

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaidYearFive
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Lessee, Noncancelable Operating Lease, Liability, to be Paid, Year Four

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaidYearFour
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Lessee, Noncancelable Operating Lease, Liability, to be Paid, Year One

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaidYearOne
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Lessee, Noncancelable Operating Lease, Liability, to be Paid, Year Three

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaidYearThree
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Lessee, Noncancelable Operating Lease, Liability, to be Paid, Year Two

No definition available.

Name:	wlfc_LesseeNoncancelableOperatingLeaseLiabilityToBePaidYearTwo
Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant