Comprehensive Income

12 Months Ended

Dec. 31, 2011

Comprehensive Income or Shareholders' Equity [Abstract]

Comprehensive Income

(12)  Comprehensive Income

Comprehensive income is defined as all changes in shareholders’ equity, except those arising from transactions with shareholders. Comprehensive income includes net income and other comprehensive income, which for the Corporation consists of changes in unrealized appreciation or depreciation of investments carried at fair value, changes in unrealized other-than-temporary impairment losses on investments, changes in foreign currency translation gains or losses and changes in postretirement benefit costs not yet recognized in net income.

The components of other comprehensive income or loss were as follows:

	Years Ended December 31
	2011									2010									2009
	Before			Income						Before			Income						Before			Income
	Tax			Tax			Net			Tax			Tax			Net			Tax			Tax			Net
	(in millions)
Unrealized holding gains arising during the year	$	1,029		$	359		$	670		$	230		$	81		$	149		$	1,930		$	675		$	1,255
Unrealized other-than-temporary impairment losses arising during the year		(1	)		—			(1	)		(3	)		(1	)		(2	)		(14	)		(5	)		(9	)
Reclassification adjustment for realized gains included in net income		81			28			53			110			39			71			44			15			29
Net unrealized gains recognized in other comprehensive income or loss		947			331			616			117			41			76			1,872			655			1,217
Foreign currency translation gains (losses)		6			2			4			(28	)		(10	)		(18	)		262			92			170
Change in postretirement benefit costs not yet recognized in net income		(329	)		(114	)		(215	)		20			8			12			134			36			98
Total other comprehensive income	$	624		$	219		$	405		$	109		$	39		$	70		$	2,268		$	783		$	1,485