Debt Obligations - Schedule of Notes Payable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Oct. 31, 2023	Dec. 31, 2022
Long Term Debt [Line Items]
Gross amount of debt	$ 1,827,059,000		$ 1,862,089,000
Less: unamortized debt issuance costs and note discounts	(24,178,000)		(14,811,000)
Total debt obligations	1,802,881,000		1,847,278,000
WEST V
Long Term Debt [Line Items]
Fixed rate (as a percent)		8.00%
Revolving credit facility
Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity		$ 500,000,000
Revolving credit facility | Maturity in March 2024
Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	49,800,000
Revolving credit facility | Maturity in June 2024
Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	158,200,000
Revolving credit facility | Maturity In June 2025
Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	500,000,000.0
Credit facility at a floating rate of interest of one-month term Secured Overnight Financing Rate (“SOFR”) plus 1.75% at December 31, 2023, secured by engines. The facility has a committed amount of $708.0 million at December 31, 2023. $49.8 million revolves until the earlier of the final WEST VII novated asset or the maturity date of March 31, 2024, $158.2 million revolves until the maturity date of June 2024, and $500.0 million revolves until the maturity date of June 2025.
Long Term Debt [Line Items]
Line of credit facility outstanding amount	$ 353,000,000		727,000,000
West Vii Series a 2023 Term Notes Payable at a Fixed Rate of Interest of 8.00%, Maturing in October 2048, Secured by Engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	8.00%
Gross amount of debt	$ 406,894,000		0
WEST VI Series A 2021 term notes payable at a fixed rate of interest of 3.10%, maturing in May 2046, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	3.10%
Gross amount of debt	$ 252,986,000		262,779,000
WEST VI Series B 2021 term notes payable at a fixed rate of interest of 5.44%, maturing in May 2046, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	5.44%
Gross amount of debt	$ 35,142,000		36,502,000
WEST VI Series C 2021 term notes payable at a fixed rate of interest of 7.39%, maturing in May 2046, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	7.39%
Gross amount of debt	$ 12,361,000		14,738,000
WEST V Series A 2020 term notes payable at a fixed rate of interest of 3.23%, maturing in March 2045, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	3.23%
Gross amount of debt	$ 240,371,000		255,136,000
WEST V Series B 2020 term notes payable at a fixed rate of interest of 4.21%, maturing in March 2045, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	4.21%
Gross amount of debt	$ 33,485,000		35,542,000
WEST V Series C 2020 term notes payable at a fixed rate of interest of 6.66%, maturing in March 2045, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	6.66%
Gross amount of debt	$ 10,695,000		13,314,000
WEST IV Series A 2018 term notes payable at a fixed rate of interest of 4.75%, maturing in September 2043, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	4.75%
Gross amount of debt	$ 212,157,000		238,072,000
WEST IV Series B 2018 term notes payable at a fixed rate of interest of 5.44%, maturing in September 2043, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	5.44%
Gross amount of debt	$ 29,024,000		36,386,000
WEST III Series A 2017 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	4.69%
Gross amount of debt	$ 175,705,000		209,061,000
WEST III Series B 2017 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042, secured by engines
Long Term Debt [Line Items]
Fixed rate (as a percent)	6.36%
Gross amount of debt	$ 23,592,000		30,255,000
Note payable at a fixed rate of interest of 4.59%, maturing in January 2032, secured by an engine
Long Term Debt [Line Items]
Fixed rate (as a percent)	4.59%
Gross amount of debt	$ 22,610,000		0
Note payable at a fixed rate of interest of 4.23%, maturing in July 2031, secured by an engine
Long Term Debt [Line Items]
Fixed rate (as a percent)	4.23%
Gross amount of debt	$ 17,802,000		0
Note payable at a fixed rate of interest of 3.18%, maturing in July 2024, secured by an aircraft
Long Term Debt [Line Items]
Fixed rate (as a percent)	3.18%
Gross amount of debt	$ 1,235,000		$ 3,304,000
Revolving credit facility | Credit facility at a floating rate of interest of one-month term Secured Overnight Financing Rate (“SOFR”) plus 1.75% at December 31, 2023, secured by engines. The facility has a committed amount of $708.0 million at December 31, 2023. $49.8 million revolves until the earlier of the final WEST VII novated asset or the maturity date of March 31, 2024, $158.2 million revolves until the maturity date of June 2024, and $500.0 million revolves until the maturity date of June 2025.
Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 708,000,000
Secured Overnight Financing Rate (SOFR) | Credit facility at a floating rate of interest of one-month term Secured Overnight Financing Rate (“SOFR”) plus 1.75% at December 31, 2023, secured by engines. The facility has a committed amount of $708.0 million at December 31, 2023. $49.8 million revolves until the earlier of the final WEST VII novated asset or the maturity date of March 31, 2024, $158.2 million revolves until the maturity date of June 2024, and $500.0 million revolves until the maturity date of June 2025.
Long Term Debt [Line Items]
Variable rate (as a percent)	1.75%