Investments - Summarized Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Consolidated Statements of Income
Revenue	$ 418,555		$ 311,927
Expenses	354,333		302,072
WMES net income	43,781		5,439
Consolidated Balance Sheets
Total assets	2,652,344	[1]	2,575,217
Total liabilities	2,163,417	[2]	2,120,640
Total WMES net equity	438,963		404,688	$ 375,885
WMES
Consolidated Statements of Income
Revenue	47,617		52,106
Expenses	46,317		51,953
WMES net income	1,300		153
Consolidated Balance Sheets
Total assets	236,732		267,580
Total liabilities	150,604		183,083
Total WMES net equity	$ 86,128		$ 84,497

[1] Total assets at December 31, 2023 and 2022 include the following assets of variable interest entities (“VIEs”) that can only be used to settle the liabilities of the VIEs: Restricted cash $160,958 and $76,870; Equipment $1,518,050 and $1,167,970; Maintenance rights $7,806 and $5,433; Notes receivable $91,960 and $80,220; Investments in sales-type leases $3,564 and $0; and Other assets $13,339 and $6,470, respectively.

[2] Total liabilities at December 31, 2023 and 2022 include the following liabilities of VIEs for which the VIEs’ creditors do not have recourse to Willis Lease Finance Corporation: Debt obligations $1,411,680 and $1,118,721, respectively.