Consolidated Statements Of Shareholders' Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net unrealized appreciation on investments, Change in period, income tax (expense) benefit	$ (93)	$ 56
Cumulative translation adjustment, Change in period, income tax(expense) benefit	(8)	55
Pension liability adjustment, Change in period, income tax (expense) benefit	3	(8)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Unrealized appreciation on investments, Change in period before reclassification to AOCI, income tax (expense) benefit	9	30
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	(3)	5
Income tax expense from reclassification of unrealized gains	$ (90)	$ 51