Segment Information - Summarized Financial Information Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Total revenues	$ 1,606	$ 1,186	$ 4,295	$ 3,622
Employee compensation and benefits	793	607	2,116	1,823
Other operating expenses	276	165	672	499
(Gain)/loss on disposal		(1)	1	(30)
Interest expense	100	50	197	147
Change in estimated acquisition earn-out payables	11	(8)	18	(9)
Income before income taxes	311	317	1,050	1,028
Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,564	1,165	4,218	3,575
Income before income taxes	419	330	1,229	1,072
Operating Segments | Retail
Segment Reporting Information [Line Items]
Total revenues	883	641	2,487	2,093
Employee compensation and benefits	493	364	1,326	1,118
Other operating expenses	153	107	395	334
(Gain)/loss on disposal	0	(1)	1	(2)
Depreciation and amortization	74	35	158	101
Interest expense	(11)	18	19	56
Change in estimated acquisition earn-out payables	10	(2)	13	(2)
Income before income taxes	164	120	575	488
Operating Segments | Specialty Distribution
Segment Reporting Information [Line Items]
Total revenues	681	524	1,731	1,482
Employee compensation and benefits	252	193	653	570
Other operating expenses	132	95	321	272
(Gain)/loss on disposal	0	0	0	(28)
Depreciation and amortization	32	21	71	59
Interest expense	9	10	27	32
Change in estimated acquisition earn-out payables	1	(5)	5	(7)
Income before income taxes	255	210	654	584
Segment Reconciling Items
Segment Reporting Information [Line Items]
Total revenues	42	21	77	47
Income before income taxes	$ (108)	$ (13)	$ (179)	$ (44)