v3.19.3.a.u2
Document and Entity Information - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Jun. 30, 2019
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Entity Registrant Name BlackRock, Inc.    
Entity Central Index Key 0001364742    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   154,827,534  
Entity Public Float     $ 71.9
Entity File Number 001-33099    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 32-0174431    
Entity Address, Address Line One 55 East 52nd Street    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10055    
City Area Code 212    
Local Phone Number 810-5300    
Document Annual Report true    
Document Transition Report false    
Entity Interactive Data Current Yes    
Documents Incorporated by Reference

The following documents are incorporated by reference herein:

Portions of the definitive Proxy Statement of BlackRock, Inc. to be filed pursuant to Regulation 14A of the general rules and regulations under the Securities Exchange Act of 1934, as amended, for the 2020 annual meeting of stockholders to be held on May 21, 2020 (“Proxy Statement”) are incorporated by reference into Part III of this Form 10-K.

   
Common Stock, $.01 Par Value [Member]      
Document Information [Line Items]      
Trading Symbol BLK    
Title of 12(b) Security Common Stock, $.01 par value    
Security Exchange Name NYSE    
1.250% Notes due 2025 [Member]      
Document Information [Line Items]      
Trading Symbol BLK25    
Title of 12(b) Security 1.250% Notes due 2025    
Security Exchange Name NYSE