Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions			12 Months Ended
	Jun. 06, 2023 shares	Apr. 12, 2023 USD ($) shares	Dec. 31, 2024 USD ($) Segment institution shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 04, 2024 USD ($)	Feb. 13, 2024 USD ($)
Significant Accounting Policies [Line Items]
Number of reporting unit with negative carrying value | Segment			1
Customer reimbursable engineering			$ 29	$ 12
Government grants			$ 19	$ 14	$ 25
Number of third party financial institutions | institution			2
Supplier finance program, obligation, statement of financial position [extensible enumeration]			Accounts payable	Accounts payable
Net actuarial gain (losses) recognition, minimum percentage			10.00%
Stock repurchase program, authorized amount						$ 250	$ 350
Payments for dividends of convertible preferred stock			$ 0	$ 25	0
Stock repurchased during period (in shares) | shares			33,493,224
Payments for repurchase of common stock			$ 296	213	0
Series A Preferred Stock
Significant Accounting Policies [Line Items]
Stock repurchase program, authorized amount		$ 570
Shares of Garrett common stock distributed | shares	175,337,712
Series A Preferred Stock | Additional Amounts And Accumulated Dividends | Related Party
Significant Accounting Policies [Line Items]
Preferred stock dividends (in shares) | shares		7,276,036
Common Stock
Significant Accounting Policies [Line Items]
Issuance of common stock for preference dividends (in shares) | shares	25,577,517
Conversion of stock, shares issued (in shares) | shares	175,337,712
Trane Technologies | Related Party | Purchase of goods and services
Significant Accounting Policies [Line Items]
Related party transaction, amounts of transaction			1
Accounts payable, trade			0
Honeywell International, Inc
Significant Accounting Policies [Line Items]
Related party transaction, amounts of transaction				2	9
Honeywell International, Inc | Related Party
Significant Accounting Policies [Line Items]
Payments for dividends of convertible preferred stock		$ 1
Honeywell International, Inc | Series A Preferred Stock | Related Party
Significant Accounting Policies [Line Items]
Shares of Garrett common stock distributed | shares		4,196,330
Honeywell International, Inc | Common Stock | Related Party
Significant Accounting Policies [Line Items]
Issuance of common stock for preference dividends (in shares) | shares		438,009
Centerbridge Partners, L.P. and Oaktree Capital Management, L.P. | Related Party
Significant Accounting Policies [Line Items]
Payments for dividends of convertible preferred stock		$ 9
Centerbridge Partners, L.P. and Oaktree Capital Management, L.P. | Series A Preferred Stock | Related Party
Significant Accounting Policies [Line Items]
Shares of Garrett common stock distributed | shares		65,334,277
Stock repurchased during period (in shares) | shares	69,707,719
Centerbridge Partners, L.P. and Oaktree Capital Management, L.P. | Common Stock | Related Party
Significant Accounting Policies [Line Items]
Issuance of common stock for preference dividends (in shares) | shares		6,819,540
Sessa Capital and its affiliates | Related Party
Significant Accounting Policies [Line Items]
Payments for dividends of convertible preferred stock		$ 2
Sessa Capital and its affiliates | Common Stock | Related Party
Significant Accounting Policies [Line Items]
Issuance of common stock for preference dividends (in shares) | shares		1,731,900
Conversion of stock, shares issued (in shares) | shares		16,592,384
Centerbridge | Related Party
Significant Accounting Policies [Line Items]
Payments for repurchase of common stock			$ 25
Centerbridge | Common Stock | Related Party
Significant Accounting Policies [Line Items]
Stock repurchased during period (in shares) | shares			2,808,988
Guaranteed bank notes
Significant Accounting Policies [Line Items]
Supplier finance program payment timing period			6 months
Cost of Goods Sold
Significant Accounting Policies [Line Items]
Research and development cost			$ 187	175	153
Engineering-related expenses			(26)	(12)	11
Research and development expense, customer reimbursement			$ 67	$ 46	$ 25
Minimum | Buildings and improvements
Significant Accounting Policies [Line Items]
Estimated useful lives			10 years
Minimum | Machinery and equipment
Significant Accounting Policies [Line Items]
Estimated useful lives			2 years
Minimum | Tooling
Significant Accounting Policies [Line Items]
Estimated useful lives			3 years
Minimum | Software
Significant Accounting Policies [Line Items]
Estimated useful lives			5 years
Maximum | Buildings and improvements
Significant Accounting Policies [Line Items]
Estimated useful lives			50 years
Maximum | Machinery and equipment
Significant Accounting Policies [Line Items]
Estimated useful lives			16 years
Maximum | Tooling
Significant Accounting Policies [Line Items]
Estimated useful lives			10 years
Maximum | Software
Significant Accounting Policies [Line Items]
Estimated useful lives			7 years