Income Taxes (tables)

12 Months Ended

Dec. 31, 2016

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)	2016			2015			2014
Composition of income tax expense included in the consolidated statement of income
Current expense:
Federal	$	899		$	1,144		$	1,216
Foreign	21			29			28
State	8			9			10
Total current tax expense	928			1,182			1,254
Deferred expense:
Federal	110			117			121
Foreign	1			2			22
Total deferred tax expense	111			119			143
Total income tax expense included in the consolidated statement of income	1,039			1,301			1,397
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	(289		)	(448		)	68
Total income tax expense included in the consolidated financial statements	$	750		$	853		$	1,465

Effective tax rate [Table Text Block]

(for the year ended December 31, in millions)	2016			2015			2014
Income before income taxes
U.S.	$	3,946		$	4,621		$	4,899
Foreign	107			119			190
Total income before income taxes	4,053			4,740			5,089
Effective tax rate
Statutory tax rate	35		%	35		%	35		%
Expected federal income tax expense	1,419			1,659			1,781
Tax effect of:
Nontaxable investment income	(323		)	(345		)	(379		)
Other, net	(57		)	(13		)	(5		)
Total income tax expense	$	1,039		$	1,301		$	1,397
Effective tax rate	26		%	27		%	27		%

Deferred tax assets and liabilities [Table Text Block]

(at December 31, in millions)	2016		2015
Deferred tax assets
Claims and claim adjustment expense reserves	$	664	$	691
Unearned premium reserves	760		731
Compensation-related liabilities	268		326
Other	272		320
Total gross deferred tax assets	1,964		2,068
Less: valuation allowance	3		—
Adjusted gross deferred tax assets	1,961		2,068
Deferred tax liabilities
Deferred acquisition costs	604		580
Investments	592		867
Internally developed software	157		134
Other	143		191
Total gross deferred tax liabilities	1,496		1,772
Net deferred tax asset	$	465	$	296

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

(in millions)	Amount		Year of expiration
Brazil	$	8	None
United Kingdom	$	106	None

Reconciliation of unrecognized tax benefits [Table Text Block]

(in millions)	2016			2015
Balance at January 1	$	16		$	23
Additions for tax positions of prior years	3			2
Reductions for tax positions of prior years	(6		)	(9		)
Additions based on tax positions related to current year	—			—
Balance at December 31	$	13		$	16