Debt Obligations - Additional Information (Details)	1 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2025 USD ($) debtSeries	Jun. 30, 2025 USD ($) debtSeries	Dec. 31, 2024 USD ($)
Long Term Debt
Variable rate (as a percent)		4.45%	4.37%
Gross amount of debt	$ 2,834,137,000	$ 2,834,137,000	$ 2,292,726,000
Note payable at a fixed rate of interest of 5.00%, maturing in February 2033, secured by an engine
Long Term Debt
Gross amount of debt	$ 20,643,000	$ 20,643,000	20,780,000
Fixed rate (as a percent)	5.00%	5.00%
Note payable at a fixed rate of interest of 4.59%, maturing in November 2032, secured by an engine
Long Term Debt
Gross amount of debt	$ 21,828,000	$ 21,828,000	22,094,000
Fixed rate (as a percent)	4.59%	4.59%
Note payable at a fixed rate of interest of 4.23%, maturing in June 2032, secured by an engine
Long Term Debt
Gross amount of debt	$ 17,662,000	$ 17,662,000	17,710,000
Fixed rate (as a percent)	4.23%	4.23%
Note payable at a fixed rate of interest of 5.17%, maturing in March 2033, secured by an engine
Long Term Debt
Gross amount of debt	$ 23,860,000	$ 23,860,000	0
Option to repurchase engine, price	$ 16,900,000	$ 16,900,000
Fixed rate (as a percent)	5.17%	5.17%
Note payable at a fixed rate of interest of 5.91%, maturing in March 2034, secured by an engine
Long Term Debt
Gross amount of debt	$ 21,007,000	$ 21,007,000	0
Fixed rate (as a percent)	5.91%	5.91%
Note payable at a fixed rate of interest of 5.83%, maturing in April 2034, secured by an engine
Long Term Debt
Gross amount of debt	$ 19,739,000	$ 19,739,000	0
Fixed rate (as a percent)	5.83%	5.83%
Notes Payable Due March 2032
Long Term Debt
Option to repurchase engine, price	$ 18,400,000	$ 18,400,000
Notes Payable Due January 2032
Long Term Debt
Option to repurchase engine, price	17,700,000	17,700,000
Notes Payable Due July 2031
Long Term Debt
Option to repurchase engine, price	17,000,000	17,000,000
Notes Payable Due March 2032
Long Term Debt
Option to repurchase engine, price	19,300,000	19,300,000
Notes Payable Due April 2033
Long Term Debt
Option to repurchase engine, price	17,900,000	17,900,000
WEST VIII
Long Term Debt
Debt instrument, face amount	$ 596,000,000	$ 596,000,000
Number of series issued | debtSeries	2	2
Debt instrument, expected maturity term	6 years
Debt instrument, final maturity term	25 years
WEST VIII Series A 2025 term notes payable at a fixed rate of interest of 5.58%, maturing in June 2050, secured by engines, airframes, and loan assets
Long Term Debt
Gross amount of debt	$ 524,000,000	$ 524,000,000	0
Fixed rate (as a percent)	5.58%	5.58%
Notes issue price, percentage of par	99.99721%
WEST VIII Series B 2025 term note payable at a fixed rate of interest of 6.07%, maturing in June 2050, secured by engines, airframes, and loan assets
Long Term Debt
Gross amount of debt	$ 72,000,000	$ 72,000,000	$ 0
Fixed rate (as a percent)	6.07%	6.07%
Notes issue price, percentage of par	99.99711%