Restructuring Costs (Restructuring Activities) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 53	$ 30
Jardine Lloyd Thompson Group plc
Restructuring Reserve [Roll Forward]
Liability at beginning of period	146	69	$ 69
Restructuring charges	53		427
Cash payments	(79)		(193)
Non-cash charges	(8)		(157)
Liability at end of period	112		146
Jardine Lloyd Thompson Group plc | Severance
Restructuring Reserve [Roll Forward]
Liability at beginning of period	88	35	35
Restructuring charges	19		111
Cash payments	(45)		(58)
Non-cash charges	0		0
Liability at end of period	62		88
Jardine Lloyd Thompson Group plc | Real Estate Related Costs
Restructuring Reserve [Roll Forward]
Liability at beginning of period	56	34	34
Restructuring charges	17		195
Cash payments	(17)		(25)
Non-cash charges	(7)		(148)
Liability at end of period	49		56
Jardine Lloyd Thompson Group plc | Information Technology
Restructuring Reserve [Roll Forward]
Liability at beginning of period	0	0	0
Restructuring charges	1		15
Cash payments	0		(6)
Non-cash charges	(1)		(9)
Liability at end of period	0		0
Jardine Lloyd Thompson Group plc | Consulting and Other Outside Services
Restructuring Reserve [Roll Forward]
Liability at beginning of period	2	$ 0	0
Restructuring charges	16		106
Cash payments	(17)		(104)
Non-cash charges	0		0
Liability at end of period	$ 1		$ 2