v3.8.0.1
Variable Interest Entities Reflects adoption of ASU 2015-12 - Schedule of VIE Assets and Liabilities (Detail) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Variable Interest Entity [Line Items]    
Cash and cash equivalents $ 5,978 $ 6,894
Investments:    
Trading securities ($266 debt securities of consolidated sponsored investment funds) 293  
Equity securities 648  
Other assets 2,157 1,636
Liabilities of consolidated VIEs (183,434) (187,977)
Noncontrolling interests (44) (50)
Consolidated Variable Interest Entities [Member]    
Variable Interest Entity [Line Items]    
Cash and cash equivalents 103 144
Investments:    
Trading securities ($266 debt securities of consolidated sponsored investment funds) 769 475
Equity securities 295 440
Other investments 300 312
Carried interest 273 266
Other assets 113 66
Total investments and other assets 1,750 1,559
Liabilities of consolidated VIEs (425) (369)
Noncontrolling interests (518) (375)
BlackRock's net interests in consolidated VIEs $ 910 $ 959