Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Data [Abstract]

Quarterly Financial Data

	Three Months Ended
	March 31						June 30						September 30						December 31
	2011			2010			2011			2010			2011			2010			2011			2010
	(in millions except for per share amounts)
Revenues	$	3,420		$	3,323		$	3,400		$	3,318		$	3,420		$	3,267		$	3,345		$	3,411
Losses and expenses		2,735			2,675			2,854			2,616			3,054			2,483			2,743			2,557
Federal and foreign income tax		176			184			127			184			68			212			150			234
Net income	$	509		$	464		$	419		$	518		$	298		$	572		$	452		$	620
Basic earnings per share	$	1.71		$	1.39		$	1.43		$	1.60		$	1.04		$	1.82		$	1.62		$	2.03
Diluted earnings per share	$	1.70		$	1.39		$	1.42		$	1.59		$	1.04		$	1.80		$	1.60		$	2.02
Underwriting ratios
Losses to premiums earned		62.0	%		62.3	%		63.6	%		59.5	%		70.2	%		54.5	%		59.3	%		56.1	%
Expenses to premiums written		31.7			31.3			31.3			30.9			32.4			31.7			30.6			30.9
Combined		93.7	%		93.6	%		94.9	%		90.4	%		102.6	%		86.2	%		89.9	%		87.0	%