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v3.25.4

Borrowings - Carrying Value and Fair Value of Long-Term Borrowings Determined Market Prices EUR/USD Foreign Exchange Rate (Detail) - USD ($) $ in Millions | Dec. 31, 2025 | Dec. 31, 2024 | May 30, 2023 | Dec. 31, 2021 | Apr. 30, 2020 | Jan. 31, 2020 | Apr. 30, 2019
--- | --- | --- | --- | --- | --- | --- | ---
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | $ 12,875 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (107) |  |  |  |  |  |  |
Carrying Value |  | 12,768 |  | $ 12,314 |  |  |  |  |
Fair Value |  | 12,546 |  | $ 11,700 |  |  |  |  |
3.20% Notes due 2027 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount | [2] | 700 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [2] | (1) |  |  |  |  |  |  |
Carrying Value | [2] | 699 |  |  |  |  |  |  |
Fair Value | [2] | 696 |  |  |  |  |  |  |
4.60% Notes due 2027 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 800 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (2) |  |  |  |  |  |  |
Carrying Value |  | 798 |  |  |  |  |  |  |
Fair Value |  | 810 |  |  |  |  |  |  |
4.70% Notes due 2029 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 500 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (3) |  |  |  |  |  |  |
Carrying Value |  | 497 |  |  |  |  |  |  |
Fair Value |  | 511 |  |  |  |  |  |  |
3.25% Notes due 2029 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,000 | [2] |  |  |  |  |  | $ 1,000
Unamortized Discount and Debt Issuance Costs | [1],[2] | (5) |  |  |  |  |  |  |
Carrying Value | [2] | 995 |  |  |  |  |  |  |
Fair Value | [2] | 978 |  |  |  |  |  |  |
2.40% Notes due 2030 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,000 | [2] |  |  |  |  | $ 1,000 |
Unamortized Discount and Debt Issuance Costs | [1],[2] | (3) |  |  |  |  |  |  |
Carrying Value | [2] | 997 |  |  |  |  |  |  |
Fair Value | [2] | 935 |  |  |  |  |  |  |
1.90% Notes due 2031 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,250 | [2] |  |  |  | $ 1,250 |  |
Unamortized Discount and Debt Issuance Costs | [1],[2] | (6) |  |  |  |  |  |  |
Carrying Value | [2] | 1,244 |  |  |  |  |  |  |
Fair Value | [2] | 1,123 |  |  |  |  |  |  |
2.10% Notes due 2032 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,000 | [2] |  |  | $ 1,000 |  |  |
Unamortized Discount and Debt Issuance Costs | [1],[2] | (9) |  |  |  |  |  |  |
Carrying Value | [2] | 991 |  |  |  |  |  |  |
Fair Value | [2] | 883 |  |  |  |  |  |  |
4.75% Notes due 2033 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,250 | [2] |  | $ 1,250 |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1],[2] | (15) |  |  |  |  |  |  |
Carrying Value | [2] | 1,235 |  |  |  |  |  |  |
Fair Value | [2] | 1,277 |  |  |  |  |  |  |
5.00% Notes due 2034 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,000 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (6) |  |  |  |  |  |  |
Carrying Value |  | 994 |  |  |  |  |  |  |
Fair Value |  | 1,032 |  |  |  |  |  |  |
4.90% Notes due 2035 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 500 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (5) |  |  |  |  |  |  |
Carrying Value |  | 495 |  |  |  |  |  |  |
Fair Value |  | 510 |  |  |  |  |  |  |
3.75% Notes due 2035 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,175 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (8) |  |  |  |  |  |  |
Carrying Value |  | 1,167 |  |  |  |  |  |  |
Fair Value |  | 1,187 |  |  |  |  |  |  |
5.25% Notes due 2054 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,500 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (30) |  |  |  |  |  |  |
Carrying Value |  | 1,470 |  |  |  |  |  |  |
Fair Value |  | 1,436 |  |  |  |  |  |  |
5.35% Notes due 2055 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maturity Amount |  | 1,200 |  |  |  |  |  |  |
Unamortized Discount and Debt Issuance Costs | [1] | (14) |  |  |  |  |  |  |
Carrying Value |  | 1,186 |  |  |  |  |  |  |
Fair Value |  | $ 1,168 |  |  |  |  |  |  |
[1] | The unamortized discount and debt issuance costs are being amortized over the term of the notes.
[2] | Issued by Old BlackRock and guaranteed by BlackRock, Inc.

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