Business Segment Information - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026 segment distributionChannel	Jun. 30, 2025
Segment Reporting [Abstract]
Number of operating segments | segment			1
Number of reportable segments not disclosed			one
Number of distribution channels | distributionChannel			3
Revenue Benchmark | Product Concentration Risk | Japan | Location, Statement of Income, Balance [Axis]: us-gaap:RevenuesNetOfInterestExpense
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Concentration risk	11.00%	12.00%	11.00%	12.00%