Revenue - Summary of Investment Advisory, Administration Fees and Securities Lending Revenue by Client Type and Investment Style (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Disaggregation Of Revenue [Line Items]
Total revenue	$ 6,698	$ 5,276
Revenue by Client Type [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	5,438	4,401
Revenue by Client Type [Member] \| Retail [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1,263	1,061
Revenue by Client Type [Member] \| Equity ETFs [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,406	1,793
Revenue by Client Type [Member] \| Institutional Active [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1,174	1,016
Revenue by Client Type [Member] \| Institutional Index [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	255	238
Revenue by Client Type [Member] \| Institutional [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1,429	1,254
Revenue by Client Type [Member] \| Cash Management [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	340	293
Revenue by Client Type [Member] \| Long-term [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	5,098	4,108
Revenue by Investment Style [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	5,438	4,401
Revenue by Investment Style [Member] \| Equity ETFs [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,406	1,793
Revenue by Investment Style [Member] \| Equity Non ETFs [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	342	307
Revenue by Investment Style [Member] \| Active [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,350	2,008
Revenue by Investment Style [Member] \| Cash Management [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	340	293
Revenue by Investment Style [Member] \| Long-term [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 5,098	$ 4,108