XML 30 R12.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Short-Term Deposits and Marketable Securities | 12 Months Ended
--- | ---
Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract] |
Short-Term Deposits and Marketable Securities | SHORT-TERM DEPOSITS AND MARKETABLE SECURITIES To optimize the return yield on its short-term investments, the Company invested $1,226 million of available cash in short-term deposits as of December 31, 2023, compared to $581 million as of December 31, 2022. The Company also invested available liquidity in marketable securities. Changes in the fair value of marketable securities are detailed in the tables below:
|  | December 31, 2022 |  | Purchase |  | Accretion |  | Proceeds at maturity |  | Change in fair value included in OCI* |  | December 31, 2023
U.S. Treasury debt securities |  | 679 |  |  | 1,653 |  |  | 47 |  |  | (750) |  |  | 6 |  |  | 1,635 |
Total |  | 679 |  |  | 1,653 |  |  | 47 |  |  | (750) |  |  | 6 |  |  | 1,635 |
* Other Comprehensive Income
|  | December 31, 2021 |  | Purchase |  | Accretion |  | Proceeds at maturity |  | Change in fair value included in OCI* |  | December 31, 2022
U.S. Treasury debt securities |  | — |  |  | 687 |  | 8 |  | — |  |  | (16) |  | 679
Total |  | — |  |  | 687 |  | 8 |  | — |  |  | (16) |  | 679
* Other Comprehensive Income In 2023, the Company invested $1,653 million available cash in U.S. Treasury bonds. The debt securities have an average rating of Aaa/AA+/AA+ from Moody’s, S&P and Fitch, respectively, with a weighted average maturity of 1.6 years. The debt securities are reported as current assets on the line “Marketable securities” on the consolidated balance sheet, since they represent investments of funds available for current operations. The Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of the amortized cost basis. The bonds are classified as available-for-sale financial assets and recorded at fair value as of December 31, 2023. The fair value measurement corresponds to a Level 1 fair value hierarchy measurement. The aggregate amortized cost basis of these securities totaled $1,645 million as of December 31, 2023. Marketable securities totaling $750 million at principal amount were transferred to financial institutions as part of short-term securities lending transactions, in compliance with corporate policies. The Company, acting as the securities lender, does not hold any collateral in this unsecured securities lending transaction. The Company retains effective control on the transferred securities. As of December 31, 2022, the Company held $679 million in marketable securities classified as available-for-sale debt securities. The below table details debt securities that were in an unrealized loss position as of December 31, 2023:
| December 31, 2023
| Less than 12 months | More than 12 months | Total
Description | Fair Value | Unrealized Losses | Fair Value | Unrealized Losses | Fair Value | Unrealized Losses
U.S. Treasury Bonds | 429 | (12) | 157 | (1) | 586 | (13)
Total | 429 | (12) | 157 | (1) | 586 | (13)
Debt securities that were in an unrealized gain position as of December 31, 2023, were reported at a fair value of $1,049 million with an unrealized gain of $4 million. The Company did not report any debt securities that were in an unrealized loss position for more than one year as of December 31, 2022.

X
- Definition Short-term deposits and marketable securities. + References No definition available. + Details
Name: | stm_ShortTermDepositsAndMarketableSecuritiesTextBlock
Namespace Prefix: | stm_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration