Business Segment Information - Additional Information (Details)	3 Months Ended
	Mar. 31, 2025 distributionChannel segment	Mar. 31, 2024
Segment Reporting [Abstract]
Number of operating segments | segment	1
Number of distribution channels | distributionChannel	3
Revenue Benchmark | Product Concentration Risk | Japan
Revenue, Major Customer [Line Items]
Concentration risk	12.00%	9.00%
Revenue Benchmark | Product Concentration Risk | Japan | Investment advisory and services fees
Revenue, Major Customer [Line Items]
Concentration risk	15.00%	13.00%