v3.19.2
Revenue - Summary of Details of Revenue (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Disaggregation Of Revenue [Line Items]        
Total revenue $ 3,524 $ 3,605 $ 6,870 $ 7,188
Investment Advisory, Administration Fees and Securities Lending Revenue [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 2,903 2,944 5,708 5,891
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Equity Active Product [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 385 426 760 864
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Equity iShares ETFs [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 870 911 1,717 1,837
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Equity Non-ETF Index [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 163 187 327 363
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Equity [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 1,418 1,524 2,804 3,064
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Fixed Income Active [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 474 458 931 914
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Fixed Income iShares ETFs [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 234 207 454 415
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Fixed Income Non-ETF Index [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 98 101 195 194
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Fixed Income [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 806 766 1,580 1,523
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Multi-asset [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 288 295 564 591
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Alternatives [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 244 202 472 405
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Alternatives [Member] | Illiquid Alternatives [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 118 83 228 160
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Alternatives [Member] | Liquid Alternatives [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 102 93 196 194
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Alternatives [Member] | Currency and Commodities [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 24 26 48 51
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Cash Management [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 147 157 288 308
Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | Long-term [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 2,756 2,787 5,420 5,583
Investment Advisory Performance Fees [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 64 91 90 161
Investment Advisory Performance Fees [Member] | Equity [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 4 43 4 61
Investment Advisory Performance Fees [Member] | Fixed Income [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue   (1) 2 2
Investment Advisory Performance Fees [Member] | Multi-asset [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 6 9 6 14
Investment Advisory Performance Fees [Member] | Alternatives [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 54 40 78 84
Investment Advisory Performance Fees [Member] | Alternatives [Member] | Illiquid Alternatives [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 15 2 35 2
Investment Advisory Performance Fees [Member] | Alternatives [Member] | Liquid Alternatives [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 39 38 43 82
Technology Services Revenue [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 237 198 441 382
Distribution Fees [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 267 294 529 605
Distribution Fees [Member] | Retrocessions [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 164 181 325 373
Distribution Fees [Member] | 12b-1 Fees (US Mutual Funds Distribution Fees) [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 88 103 177 211
Distribution Fees [Member] | Other Distribution Fees [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 15 10 27 21
Advisory and Other Revenue [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 53 78 102 149
Advisory and Other Revenue [Member] | Advisory [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue 22 33 41 54
Advisory and Other Revenue [Member] | Other [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenue $ 31 $ 45 $ 61 $ 95