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No definition available.

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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- Definition

With respect to a business combination completed during the period, this element provides a description of the business, other than the name, which may include the industry, size, products and other important information.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

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The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Price of a single share of a number of saleable stocks of a company.

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No definition available.

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Per share or per unit amount of equity securities issued.

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No definition available.

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Number of shares of stock issued during the period pursuant to acquisitions.

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Value of stock issued pursuant to acquisitions during the period.

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Acquisitions - Additional Information (Detail) $ / shares in Units, shares in Millions, $ in Millions, £ in Billions				3 Months Ended		6 Months Ended
	Mar. 03, 2025 USD ($)	Mar. 03, 2025 GBP (£)	Oct. 01, 2024 USD ($) shares	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) shares	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)	Sep. 30, 2024 $ / shares	Mar. 31, 2024 USD ($)	Jan. 01, 2023 USD ($)
Business Acquisition [Line Items]
Amortization of intangible assets				$ 137	$ 39	$ 254	$ 77
Contingent consideration liabilities				4,472		4,472		$ 4,302
Debt instrument, aggregate principal amount				12,874		12,874
Preqin Holding Limited [Member]
Business Acquisition [Line Items]
Cash paid	$ 3,219	£ 2.5
Amortization of intangible assets				$ 29		$ 38
Acquired finite-lived intangible assets weighted-average useful life						8 years
Description of acquisition	On March 3, 2025, BlackRock completed the acquisition of 100% of the shares of Preqin Holding Limited (the "Preqin Transaction" or "Preqin"), a leading provider of private markets data, for £2.5 billion (or approximately $3.2 billion) in cash.	On March 3, 2025, BlackRock completed the acquisition of 100% of the shares of Preqin Holding Limited (the "Preqin Transaction" or "Preqin"), a leading provider of private markets data, for £2.5 billion (or approximately $3.2 billion) in cash.
Business acquisition, percentage of equity interest acquired	100.00%	100.00%
Preqin Holding Limited [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Finite lived intangible assets estimated useful lives				10 years		10 years
Preqin Holding Limited [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Finite lived intangible assets estimated useful lives				5 years		5 years
Global Infrastructure Management, LLC [Member]
Business Acquisition [Line Items]
Cash paid			$ 2,913
Description of acquisition			On October 1, 2024, BlackRock completed the acquisition of 100% of the issued and outstanding limited liability company interests of Global Infrastructure Management, LLC ("GIP" or the "GIP Transaction")
Business acquisition, percentage of equity interest acquired			100.00%
Contingent consideration liabilities			$ 4,200
Goodwill, expected tax deductible amount			$ 180
Debt instrument, aggregate principal amount										$ 3,000	$ 3,000
Global Infrastructure Management, LLC [Member] \| Common Stock [Member]
Business Acquisition [Line Items]
Number of shares issued \| shares			6.9
Stock issued during period, value			$ 5,900
Stock price \| $ / shares									$ 950
Shares issued, price per share \| $ / shares									$ 855
Global Infrastructure Management, LLC [Member] \| March 2024 Notes [Member]
Business Acquisition [Line Items]
Cash paid			$ 3,000
Global Infrastructure Management, LLC [Member] \| Maximum [Member] \| First contingent payment [Member]
Business Acquisition [Line Items]
Contingent payments \| shares			5.2			5.2
Global Infrastructure Management, LLC [Member] \| Minimum [Member] \| First contingent payment [Member]
Business Acquisition [Line Items]
Contingent payments \| shares			4.0			4.0