Schedule II - Condensed Financial Information, Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 2,795	$ 2,978	$ 4,690	$ 1,605
Other assets	2,407	2,355
Total assets	54,336	53,734
Liabilities:
Short-term debt	233	201
Long-term debt	5,014	4,986
Total liabilities	43,659	43,851
Shareholders Equity:
Common stock (shares issued,366; authorized, 600)	92	92
Additional paid-in capital	3,356	3,295
Net unrealized appreciation, fixed maturities	473	883
Net unrealized appreciation, equity securities	4	4
Net unrealized depreciation, derivatives	(19)	(28)
Net translation foreign currencies	82	69
Postretirement benefits liability adjustment	(1,060)	(1,599)
Accumulated other comprehensive loss	(520)	(671)
Retained earnings	13,676	12,330
Less treasury stock, at cost	(6,037)	(5,277)
Total shareholders' equity	10,567	9,769
Total liabilities and equity	54,336	53,734
Parent Company [Member]
Assets
Cash and cash equivalents	0	115	0	0
Investments in subsidiaries	16,932	16,125
Intercompany	40	37
Other assets	435	729
Total assets	17,407	17,006
Liabilities:
Intercompany	1,043	289
Short-term debt	100	200
Long-term debt	4,871	4,870
Other liabilities	826	1,878
Total liabilities	6,840	7,237
Shareholders Equity:
Common stock (shares issued,366; authorized, 600)	92	92
Additional paid-in capital	3,356	3,295
Net unrealized appreciation, fixed maturities	473	883
Net unrealized appreciation, equity securities	4	4
Net unrealized depreciation, derivatives	(19)	(28)
Net translation foreign currencies	82	69
Postretirement benefits liability adjustment	(1,060)	(1,599)
Accumulated other comprehensive loss	(520)	(671)
Retained earnings	13,676	12,330
Less treasury stock, at cost	(6,037)	(5,277)
Total shareholders' equity	10,567	9,769
Total liabilities and equity	$ 17,407	$ 17,006