Revenue - Summary of Investment Advisory, Administration Fees and Securities Lending Revenue by Client Type and Investment Style (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation Of Revenue [Line Items]
Total revenue	$ 7,084	$ 5,423	$ 13,782	$ 10,699
Revenue by Client Type [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	5,726	4,454	11,164	8,855
Revenue by Client Type [Member] \| Retail [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1,323	1,053	2,586	2,114
Revenue by Client Type [Member] \| Equity ETFs [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,595	1,875	5,001	3,668
Revenue by Client Type [Member] \| Institutional Active [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1,176	981	2,350	1,997
Revenue by Client Type [Member] \| Institutional Index [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	289	241	544	479
Revenue by Client Type [Member] \| Institutional [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1,465	1,222	2,894	2,476
Revenue by Client Type [Member] \| Cash Management [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	343	304	683	597
Revenue by Client Type [Member] \| Long-term [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	5,383	4,150	10,481	8,258
Revenue by Investment Style [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	5,726	4,454	11,164	8,855
Revenue by Investment Style [Member] \| Equity ETFs [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,595	1,875	5,001	3,668
Revenue by Investment Style [Member] \| Equity Non ETFs [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	385	313	727	620
Revenue by Investment Style [Member] \| Active [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,403	1,962	4,753	3,970
Revenue by Investment Style [Member] \| Cash Management [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	343	304	683	597
Revenue by Investment Style [Member] \| Long-term [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 5,383	$ 4,150	$ 10,481	$ 8,258