Schedule II - Condensed Financial Information, Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 3,224	$ 1,968	$ 2,381	$ 1,420
Short-term investments	997	381
Other assets	2,611	2,476
Total assets	60,762	57,088
Liabilities:
Short-term debt	271	149
Long-term debt, carrying value	4,780	5,020
Total liabilities	46,712	44,975
Shareholders Equity:
Common stock (shares issued, 296; authorized, 600)	74	74
Additional paid-in capital	2,884	2,859
Accumulated other comprehensive loss	(715)	(1,250)
Retained earnings	13,487	12,121
Less treasury stock, at cost	(1,756)	(1,769)
Total shareholders' equity	13,974	12,035
Total liabilities and equity	$ 60,762	$ 57,088