Consolidated Statements Of Shareholders' Equity (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Net unrealized appreciation on investments, Change in period, income tax (expense) benefit	$ 112	$ (161)
Cumulative translation adjustment, Change in period, income tax(expense) benefit	35	7
Pension liability adjustment, Change in period, income tax (expense) benefit	(2)	3
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Tax	102	(168)
Income tax benefit (expense) from reclassification of unrealized gains	$ 10	$ 7