Debt - Senior Credit Facilities Narrative (Details) ¥ in Millions, $ in Millions			1 Months Ended			3 Months Ended				12 Months Ended
	Apr. 14, 2025 USD ($)	Feb. 12, 2025	Nov. 30, 2024 USD ($)	Jan. 31, 2023 CNY (¥)	Mar. 31, 2022 USD ($)	Mar. 31, 2025 USD ($)	Mar. 31, 2025 CNY (¥)	Mar. 31, 2024 USD ($)	Mar. 31, 2024 CNY (¥)	Dec. 31, 2024 USD ($)	Dec. 31, 2024 CNY (¥)	Mar. 06, 2025 CNY (¥)	Dec. 31, 2024 CNY (¥)	Jun. 30, 2024 CNY (¥)	Apr. 30, 2024 CNY (¥)	Dec. 31, 2023 CNY (¥)
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage						100.00%	100.00%
Proceeds from short-term borrowings						$ 548		$ 146
Repayments of Short-term Debt						341		418
Proceeds from Issuance of Long-Term Debt						$ 2,739		$ 111
5 Year Delayed-Draw Term Loan | Term Loan Facility
Debt Instrument [Line Items]
Debt instrument, term					5 years
Debt instrument, face amount					$ 1,000
January 2023 CSIT One Year Working Capital Term Loan | January 2023 CSIT One Year Working Capital Term Loan
Debt Instrument [Line Items]
Debt instrument, term				12 months
Debt instrument, face amount | ¥				¥ 800
Repayments of Debt | ¥									¥ 800
January 2023 CSIT One Year Working Capital Term Loan | January 2023 CSIT One Year Working Capital Term Loan | Variable Interbank Interest Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				0.50%
June 2024 CNC Three Year Working Capital Loan | June 2024 CNC Three Year Working Capital Loan
Debt Instrument [Line Items]
Debt instrument, face amount | ¥														¥ 800
Debt Instrument, Interest Rate, Stated Percentage														2.75%
Proceeds from Issuance of Long-Term Debt | ¥											¥ 760
Secured Debt | Amended restated receivable purchasing facility
Debt Instrument [Line Items]
Percentage of fair value of sales receivables						100.00%	100.00%
Transfer of financial assets accounted for as sales, amount derecognized						$ 352				$ 1,500
Proceeds collected on accounts receivable sold under factoring facilities						347				1,500
Trade Receivables Pledged As Collateral						$ 147
Europe Factoring Agreements
Debt Instrument [Line Items]
Transfer of financial assets accounted for as sales, non-recourse basis, account receivable percentage						100.00%
Japan Factoring Agreements
Debt Instrument [Line Items]
Transfer of financial assets accounted for as sales, non-recourse basis, account receivable percentage						100.00%
Singapore Factoring Agreements
Debt Instrument [Line Items]
Transfer of financial assets accounted for as sales, non-recourse basis, account receivable percentage						90.00%
China Factoring Agreements
Debt Instrument [Line Items]
Transfer of financial assets accounted for as sales, non-recourse basis, account receivable percentage						100.00%
China, Europe, Japan and Singapore Factoring Agreements
Debt Instrument [Line Items]
Transfer of financial assets accounted for as sales, amount derecognized						$ 161				700
Proceeds collected on accounts receivable sold under factoring facilities						170				640
Master Discounting Agreement
Debt Instrument [Line Items]
Transfer of financial assets accounted for as sales, amount derecognized						15				$ 100
November 2024 US Term Loan | Term Loan Facility
Debt Instrument [Line Items]
Debt instrument, term			364 days
Debt instrument, face amount			$ 1,000
Proceeds from short-term borrowings						500
Repayments of Short-term Debt						$ 300
November 2024 US Term Loan | Term Loan Facility | Subsequent Event
Debt Instrument [Line Items]
Repayments of Short-term Debt	$ 100
November 2024 US Term Loan | Term Loan Facility | Minimum | Term SOFR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.30%
November 2024 US Term Loan | Term Loan Facility | Minimum | Base Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			0.30%
November 2024 US Term Loan | Term Loan Facility | Maximum | Term SOFR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			2.25%
November 2024 US Term Loan | Term Loan Facility | Maximum | Base Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.25%
March 2025 CNC Three Year Working Capital Loan | March 2025 CNC Three Year Working Capital Loan
Debt Instrument [Line Items]
Debt instrument, face amount | ¥												¥ 750
U.S. Credit Agreements | Minimum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)		0.25%
U.S. Credit Agreements | Maximum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)		0.30%
Various senior notes | Maximum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)		0.50%
December 2024 CNC Three Year Working Capital Loan | December 2024 CNC Three Year Working Capital Loan
Debt Instrument [Line Items]
Debt instrument, face amount | ¥													¥ 1,000
Proceeds from Issuance of Long-Term Debt | ¥							¥ 500
Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					$ 1,750
Revolving Credit Facility | Revolving Credit Facility | Minimum | Variable Interbank Interest Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate						1.00%	1.00%
Revolving Credit Facility | Revolving Credit Facility | Maximum | Variable Interbank Interest Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate						2.00%	2.00%
Revolving Credit Facility | China Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | ¥				¥ 1,750									¥ 550		¥ 750
December 2023 CNC Three Year Working Capital Loan | December 2023 CNC Three Year Working Capital Loan
Debt Instrument [Line Items]
Debt instrument, face amount | ¥																¥ 800
Debt Instrument, Interest Rate, Stated Percentage																2.80%