Schedule II - Condensed Financial Information, Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 2,401	$ 1,968	$ 2,620	$ 1,420
Short-term investments	465	381
Other assets	2,788	2,476
Total assets	58,884	57,088
Liabilities:
Short-term debt	399	149
Long-term debt, carrying value	4,791	5,020
Total liabilities	46,127	44,975
Shareholders Equity:
Common stock (shares issued, 296; authorized, 600)	74	74
Additional paid-in capital	2,874	2,859
Accumulated other comprehensive loss	(988)	(1,250)
Retained earnings	12,541	12,121
Less treasury stock, at cost	(1,826)	(1,769)
Total shareholders' equity	12,675	12,035
Total liabilities and equity	$ 58,884	$ 57,088