Consolidated Statements Of Shareholders' Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Net unrealized appreciation on investments, Change in period, income tax (expense) benefit	$ (208)	$ 344
Cumulative translation adjustment, Change in period, income tax(expense) benefit	(42)	62
Pension liability adjustment, Change in period, income tax (expense) benefit	5	(7)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Unrealized appreciation on investments, Change in period before reclassification to AOCI, income tax (expense) benefit	25	61
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Unrealized appreciation on investments, Change in period before reclassification to AOCI, income tax (expense) benefit	2	12
Income tax expense from reclassification of unrealized gains	$ (210)	$ 332