Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2012

Net Pension Cost and the Amount Recognized in OCI for All Funded and Unfunded Plans

The components of net pension cost and the amount recognized in OCI for all funded and unfunded plans are as follows:

Year ended December 31, in millions	2012			2011			2010
Interest cost on PBO	$	47		$	57		$	60
Expected return on plan assets		(70	)		(81	)		(72	)
Amortization of losses		16			11			12
Net pension cost	$	(7	)	$	(13	)		—
Other changes in plan assets and benefit obligations recognized in other comprehensive income:
Net loss (gain)	$	63		$	120		$	54
Amortization of losses		(16	)		(11	)		(12	)
Total recognized in comprehensive income	$	47		$	109		$	42
Total recognized in net pension cost and comprehensive income	$	40		$	96		$	42

Changes in PBO Related to Pension Plans

The following table summarizes changes in the PBO related to our pension plans.

Year ended December 31, in millions	2012			2011
PBO at beginning of year	$	1,228		$	1,250
Interest cost		47			57
Actuarial losses (gains)		86			9
Benefit payments		(84	)		(88	)
PBO at end of year	$	1,277		$	1,228

Changes in FVA

The following table summarizes changes in the FVA.

Year ended December 31, in millions	2012			2011
FVA at beginning of year	$	918		$	914
Actual return on plan assets		92			(29	)
Employer contributions		16			121
Benefit payments		(84	)		(88	)
FVA at end of year	$	942		$	918

Funded Status of Pension Plans Recognized in Balance Sheets

The following table summarizes the funded status of the pension plans, which equals the amounts recognized in the balance sheets at December 31, 2012, and 2011.

December 31, in millions	2012			2011
Funded status (a)	$	(335	)	$	(310	)
Net prepaid pension cost recognized consists of:
Current liabilities	$	(14	)	$	(14	)
Noncurrent liabilities		(321	)		(296	)
Net prepaid pension cost recognized (b)	$	(335	)	$	(310	)

(a) The shortage of the FVA under the PBO.

(b) Represents the accrued benefit liability of the pension plans.

Plans had ABO in Excess of Plan Assets

The ABO for all of our pension plans was $1.3 billion at December 31, 2012, and $1.2 billion at December 31, 2011. As indicated in the table below, all of our plans had an ABO in excess of plan assets as follows:

December 31,
in millions	2012		2011
PBO	$	1,277	$	1,228
ABO		1,277		1,225
Fair value of plan assets		942		918

Weighted-Average Rates to Determine Actuarial Present Value of Benefit Obligations

To determine the actuarial present value of benefit obligations, we assumed the following weighted-average rates.

December 31,	2012			2011
Discount rate		3.25	%		4.00	%
Compensation increase rate		N/A			N/A

Weighted-Average Rates to Determine Net Pension Cost

To determine net pension cost, we assumed the following weighted-average rates.

Year ended December 31,	2012			2011			2010
Discount rate		4.00	%		4.75	%		5.25	%
Compensation increase rate		N/A			N/A			N/A
Expected return on plan assets		7.25			7.75			8.25

Asset Target Allocations Prescribed by the Pension Funds' Investment Policies

The following table shows the asset target allocations prescribed by the pension funds’ investment policies.

Asset Class	Target   Allocation   2012
Equity securities		46	%
Fixed income securities		28
Convertible securities		5
Other assets		21
Total		100	%

Fair Values of Pension Plan Assets by Asset Category

The following tables show the fair values of our pension plan assets by asset class at December 31, 2012, and 2011.

December 31, 2012
in millions	Level 1		Level 2		Level 3		Total
ASSET CLASS
Equity securities:
U.S.	$	216		—		—	$	216
International		29		—		—		29
Fixed income securities:
Corporate bonds — U.S.		—	$	73		—		73
Corporate bonds — International		—		10		—		10
Government and agency bonds — U.S.		—		79		—		79
Government bonds — International		—		3		—		3
State and municipal bonds		—		1		—		1
Mutual funds:
U.S. equity		13		—		—		13
International equity		6		2		—		8
Fixed income — U.S.		4		—		—		4
Fixed income — International		2		—		—		2
Common trust funds:
U.S. equity		—		24		—		24
International equity		—		147		—		147
Fixed income securities		—		5		—		5
Convertible securities		—		47		—		47
Short-term investments		—		48		—		48
Emerging markets		—		47		—		47
Real assets		—		118		—		118
Insurance company contracts		—		—	$	12		12
Multi-strategy investment funds		—		—		56		56
Total net assets at fair value	$	270	$	604	$	68	$	942

December 31, 2011
in millions	Level 1		Level 2		Level 3		Total
ASSET CLASS
Equity securities:
U.S.	$	336		—		—	$	336
International		39		—		—		39
Emerging markets		1		—		—		1
Fixed income securities:
Corporate bonds — U.S.		—	$	70		—		70
Corporate bonds — International		—		7		—		7
Government and agency bonds — U.S.		—		73		—		73
Government bonds — International		—		3		—		3
Convertible bonds — U.S.		—		1		—		1
Mutual funds:
U.S. equity		11		—		—		11
International equity		149		1		—		150
Fixed Income — U.S.		4		—		—		4
Fixed Income — International		2		—		—		2
Government and agency bonds — U.S.		72		—		—		72
Common trust funds:
U.S. equity		—		21		—		21
Fixed income securities		—		4		—		4
Convertible securities		—		44		—		44
Short-term investments		—		40		—		40
Emerging markets		—		24		—		24
Insurance company contracts		—		—	$	12		12
Multi-strategy investment funds		—		—		4		4
Total net assets at fair value	$	614	$	288	$	16	$	918

Changes in Fair Values of Level 3 Plan Assets

The following table shows the changes in the fair values of our Level 3 plan assets for the years ended December 31, 2012, and 2011.

in millions	Insurance Company Contracts			Multi- Strategy Investment Funds			Total
Balance at December 31, 2010	$	11		$	6		$	17
Actual return on plan assets:
Relating to assets held at reporting date		1			3			4
Relating to assets sold during the period		—			(4	)		(4)
Sales		—			(1	)		(1)
Balance at December 31, 2011	$	12		$	4		$	16
Actual return on plan assets:
Relating to assets held at reporting date		1			2			3
Relating to assets sold during the period		—			(3)			(3)
Purchases		—			55			55
Sales		(1	)		(2)			(3)
Balance at December 31, 2012	$	12		$	56		$	68

Pre-tax AOCI Not Yet Recognized as Net Postretirement Benefit Cost

The components of pre-tax AOCI not yet recognized as net postretirement benefit cost are shown below.

December 31,
in millions	2012			2011
Net unrecognized losses (gains)	$	5		$	8
Net unrecognized prior service benefit		(7	)		(8)
Total unrecognized AOCI	$	(2	)		—

Net Postretirement Benefit Cost and the Amount Recognized in OCI for All Funded and Unfunded Plans

The components of net postretirement benefit cost and the amount recognized in OCI for all funded and unfunded plans are as follows:

December 31,
in millions	2012			2011			2010
Service cost of benefits earned	$	1		$	1		$	1
Interest cost on APBO		3			3			3
Expected return on plan assets		(3	)		(3	)		(3)
Amortization of prior service cost		(1	)		(1	)		(1)
Net postretirement benefit cost		—			—			—
Other changes in plan assets and benefit obligations recognized in OCI:
Net (gain) loss	$	(3	)	$	8		$	1
Amortization of prior service cost		1			1			1
Total recognized in comprehensive income	$	(2	)	$	9		$	2
Total recognized in net postretirement benefit cost and comprehensive income	$	(2	)	$	9		$	2

Changes in APBO

The following table summarizes changes in the APBO.

Year ended December 31,
in millions	2012		2011
APBO at beginning of year	$	81	$	75
Service cost		1		1
Interest cost		3		3
Plan participants’ contributions		2		5
Actuarial losses (gains)		1		3
Benefit payments		(7)		(8)
Medicare retiree drug subsidy		—		2
Liability (gain)/loss due to settlement		(7)		—
APBO at end of year	$	74	$	81

Change in FVA (Other Post Retirement Benefit Plan Assets)

The following table summarizes changes in FVA.

Year ended December 31,
in millions	2012		2011
FVA at beginning of year	$	57	$	61
Employer contributions		(1)		1
Plan participants’ contributions		2		5
Benefit payments		(7)		(8)
Transfer to insurer		(7)		—
Actual return on plan assets		7		(2)
FVA at end of year	$	51	$	57

Funded Status of Postretirement Plans Recognized in Balance Sheets

The following table summarizes the funded status of the postretirement plans, which equals the amounts recognized in the balance sheets at December 31, 2012, and 2011.

December 31,
in millions	2012			2011
Funded status (a)	$	(23	)	$	(24	)
Accrued postretirement benefit cost recognized (b)		(23	)		(24	)

(a) The shortage of the FVA under the APBO.

(b) Consists entirely of noncurrent liabilities.

Weighted-Average Rates to Determine Net Postretirement Benefit Cost

To determine net postretirement benefit cost, we assumed the following weighted-average rates.

Year ended December 31,	2012			2011			2010
Discount rate		4.00	%		4.75	%		5.25	%
Expected return on plan assets		5.58			5.45			5.46

Assumptions Regarding Healthcare Cost Trend Rates

Our assumptions regarding healthcare cost trend rates are as follows:

December 31,	2012			2011
Healthcare cost trend rate assumed for the next year:
Under age 65		8.00	%		8.50	%
Age 65 and over		N/A			N/A
Rate to which the cost trend rate is assumed to decline		5.00			5.00
Year that the rate reaches the ultimate trend rate		2019			2019

Asset Target Allocation Ranges Prescribed by Trusts' Investment Policies

The following table shows the asset target allocation ranges prescribed by the trust’s investment policy.

Asset Class	Target Allocation             Range             2012
Equity securities		70 - 90	%
Fixed income securities		0 - 10
Convertible securities		0 - 10
Cash equivalents and other assets		10 - 30

Fair Values of Postretirement Plan Assets by Asset Category

The following tables show the fair values of our postretirement plan assets by asset class at December 31, 2012, and 2011.

December 31, 2012
in millions	Level 1		Level 2		Level 3		Total
ASSET CLASS
Common trust funds:
U.S. equity		—	$	26		—	$	26
International equity		—		8		—		8
Convertible securities		—		4		—		4
Short-term investments		—		4		—		4
Fixed income		—		2		—		2
Mutual funds — U.S. equity		—		7		—		7
Total net assets at fair value		—	$	51		—	$	51

December 31, 2011
in millions	Level 1		Level 2		Level 3		Total
ASSET CLASS
Common trust funds:
U.S. equity		—	$	36		—	$	36
International equity		—		8		—		8
Convertible securities		—		4		—		4
Short-term investments		—		8		—		8
Fixed income		—		1		—		1
Total net assets at fair value		—	$	57		—	$	57