Income Taxes (tables)

12 Months Ended

Dec. 31, 2015

Income Taxes disclosure

Composition of income tax expense included in consolidated statement of income and shareholders' equity [Table Text Block]

(for the year ended December 31, in millions)	2015			2014		2013
Composition of income tax expense included in the consolidated statement of income
Current expense:
Federal	$	1,144		$	1,216	$	1,059
Foreign		29			28		30
State		9			10		6
Total current tax expense		1,182			1,254		1,095
Deferred expense:
Federal		117			121		167
Foreign		2			22		10
Total deferred tax expense		119			143		177
Total income tax expense included in the consolidated statement of income		1,301			1,397		1,272
Composition of income tax expense (benefit) included in shareholders' equity
Expense (benefit) relating to share-based compensation, the changes in unrealized gain on investments, unrealized loss on foreign exchange and other items in other comprehensive income		(448	)		68		(822	)
Total income tax expense included in the consolidated financial statements	$	853		$	1,465	$	450

Effective tax rate [Table Text Block]

(for the year ended December 31, in millions)	2015			2014			2013
Income before income taxes
U.S.	$	4,621		$	4,899		$	4,804
Foreign		119			190			141
Total income before income taxes		4,740			5,089			4,945
Effective tax rate
Statutory tax rate		35	%		35	%		35	%
Expected federal income tax expense		1,659			1,781			1,731
Tax effect of:
Nontaxable investment income		(345	)		(379	)		(409	)
Other, net		(13	)		(5	)		(50	)
Total income tax expense	$	1,301		$	1,397		$	1,272
Effective tax rate		27	%		27	%		26	%

Deferred tax assets and liabilities [Table Text Block]

(at December 31, in millions)	2015		2014
Deferred tax assets
Claims and claim adjustment expense reserves	$	691	$	768
Unearned premium reserves		731		709
Compensation-related liabilities		326		345
Other		320		346
Total gross deferred tax assets		2,068		2,168
Deferred tax liabilities
Deferred acquisition costs		580		565
Investments		867		1,267
Internally developed software		134		130
Other		191		173
Total gross deferred tax liabilities		1,772		2,135
Net deferred tax asset	$	296	$	33

Net operating loss amounts by jurisdiction and year of expiration [Table Text Block]

(in millions)	Amount		Year of expiration
United States	$	4	2018
Brazil		1	None
United Kingdom		200	None

Reconciliation of unrecognized tax benefits [Table Text Block]

(in millions)	2015			2014
Balance at January 1	$	23		$	21
Additions for tax positions of prior years		2			2
Reductions for tax positions of prior years		(9	)		—
Additions based on tax positions related to current year		—			—
Balance at December 31	$	16		$	23