Schedule II (Details) - Condensed Balance Sheet - USD ($) shares in Millions, $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Balance Sheet
Fixed maturities, at fair value	$ 77,807	$ 71,160
Equity securities, at fair value	608	807
Short-term securities	5,137	3,470
Total assets	125,978	115,717
Debt	8,031	7,292
Total liabilities	101,057	94,157
Common stock (1,750.0 shares authorized; 228.2 and 232.1 shares issued and outstanding)	24,906	24,565
Retained earnings	45,591	43,516
Accumulated other comprehensive loss	(4,471)	(6,445)
Treasury stock, at cost (559.2 and 553.5 shares)	(41,105)	(40,076)
Total shareholders’ equity	24,921	21,560	$ 28,887
Total liabilities and shareholders’ equity	$ 125,978	$ 115,717
Common stock, shares authorized (in shares)	1,750.0	1,750.0
Common stock, shares issued (in shares)	228.2	232.1
Common stock, shares outstanding (in shares)	228.2	232.1
Treasury stock, at cost (in shares)	559.2	553.5
Travelers [Member]
Condensed Balance Sheet
Fixed maturities, at fair value	$ 182	$ 112
Equity securities, at fair value	241	234
Short-term securities	1,494	1,406
Investment in subsidiaries	29,946	26,098
Other assets	549	748
Total assets	32,412	28,598
Debt	7,336	6,597
Other liabilities	146	433
Total liabilities	7,482	7,030
Common stock (1,750.0 shares authorized; 228.2 and 232.1 shares issued and outstanding)	24,906	24,565
Retained earnings	45,600	43,524
Accumulated other comprehensive loss	(4,471)	(6,445)
Treasury stock, at cost (559.2 and 553.5 shares)	(41,105)	(40,076)
Total shareholders’ equity	24,930	21,568
Total liabilities and shareholders’ equity	$ 32,412	$ 28,598
Common stock, shares authorized (in shares)	1,750.0	1,750.0
Common stock, shares issued (in shares)	228.2	232.1
Common stock, shares outstanding (in shares)	228.2	232.1
Treasury stock, at cost (in shares)	559.2	553.5