Schedule II - Condensed Financial Information, Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 2,454	$ 1,968	$ 1,969	$ 1,420
Short-term investments	469	381
Other assets	2,617	2,476
Total assets	59,506	57,088
Liabilities:
Short-term debt	300	149
Long-term debt, carrying value	4,789	5,020
Total liabilities	46,071	44,975
Shareholders Equity:
Common stock (shares issued, 296; authorized, 600)	74	74
Additional paid-in capital	2,879	2,859
Accumulated other comprehensive loss	(844)	(1,250)
Retained earnings	13,046	12,121
Less treasury stock, at cost	(1,799)	(1,769)
Total shareholders' equity	13,356	12,035
Total liabilities and equity	$ 59,506	$ 57,088