Revenue (Change in Contract Assets and Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Contract Assets
Balance at January 1,	$ 357	$ 335
Additions	963	825
Transfers to accounts receivable	(844)	(805)
Effect of foreign exchange rate changes	(3)	2
Balance at December 31,	473	357
Contract Liabilities
Balance at January 1,	869	837
Cash received for performance obligations not yet fulfilled	847	822
Revenue recognized	(835)	(799)
Effect of foreign exchange rate changes	(15)	9
Balance at December 31,	866	869
Additions	963	$ 825
Mc Griff Insurance Services L L C
Contract Assets
Additions	69
Contract Liabilities
Additions	$ 69