Note 6 - Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2014

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

	Pension plans									Welfare plans
Dollars in millions	2014			2013			2012			2014			2013			2012
Service cost	$	24		$	29		$	28		$	2		$	3		$	4
Interest cost		47			43			44			15			14			16
Expected return on plan assets		(65	)		(62	)		(64	)		(7	)		(6	)		(5	)
Net amortization of prior service cost		(2	)		(2	)		(2	)		(3	)		(5	)		(3	)
Recognized actuarial loss		22			35			34			6			8			9
Net periodic benefit cost	$	26		$	43		$	40		$	13		$	14		$	21
Assumptions used to determine benefit costs
Discount rate (1)		5.0	%		4.2	%		4.6	%		4.7	%		4.0	%		4.5	%
Expected return on plan assets (1)		7.8	%		7.8	%		8.4	%		7.8	%		7.8	%		8.5	%
Rate of compensation increase (1)		3.7	%		3.7	%		3.7	%		3.7	%		3.8	%		3.8	%
Pension band increase (2)		2.0	%		2.0	%		2.0	%	n/a			n/a			n/a

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

	Pension plans						Welfare plans
Dollars in millions	2014			2013			2014			2013
Change in plan assets
Fair value of plan assets, January 1,	$	907		$	837		$	93		$	77
Actual return on plan assets		68			134			5			16
Employee contributions		-			-			2			3
Employer contributions		1			1			17			19
Benefits paid		(70	)		(65	)		(19	)		(23	)
Medicare Part D reimbursements		-			-			1			1
Fair value of plan assets, December 31,	$	906		$	907		$	99		$	93
Change in benefit obligation
Benefit obligation, January 1,	$	960		$	1,046		$	326		$	354
Service cost		24			29			2			3
Interest cost		47			43			15			14
Actuarial loss (gain)		137			(93	)		8			(26	)
Medicare Part D reimbursements		-			-			1			1
Benefits paid		(70	)		(65	)		(19	)		(23	)
Employee contributions		-			-			1			3
Benefit obligation, December 31,	$	1,098		$	960		$	334		$	326
Funded status at end of year	$	(192	)	$	(53	)	$	(235	)	$	(233	)
Amounts recognized in the Consolidated Statements of Financial Position consist of
Long-term asset (2)	$	97		$	117		$	-		$	-
Current liability		(2	)		(2	)		-			-
Long-term liability		(287	)		(168	)		(235	)		(233	)
Net liability at December 31,	$	(192	)	$	(53	)	$	(235	)	$	(233	)
Accumulated benefit obligation (1)	$	1,027		$	902		n/a			n/a
Assumptions used to determine benefit obligations
Discount rate		4.2	%		5.0	%		4.0	%		4.7	%
Rate of compensation increase		3.7	%		3.7	%		3.7	%		3.7	%
Pension band increase (3)		2.0	%		2.0	%	n/a			n/a

Schedule of Health Care Cost Trend Rates [Table Text Block]

	2014			2013
Health care cost trend rate assumed for next year		8.1	%		8.4	%
Ultimate rate to which the cost trend rate is assumed to decline		4.5	%		4.5	%
Year that reaches ultimate trend rate	2030			2030

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]

In millions	Effect on benefit obligation
1% Health care cost trend rate increase	$	15
1% Health care cost trend rate decrease		(13	)

Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block]

	Net regulatory assets					Accumulated OCI					Total
In millions	Pension plans		Welfare plans			Pension plans			Welfare plans		Pension plans			Welfare plans
December 31, 2014:
Prior service credit	$	-	$	(18	)	$	(6	)	$	-	$	(6	)	$	(18	)
Net loss		76		57			307			36		383			93
Total	$	76	$	39		$	301		$	36	$	377		$	75
December 31, 2013:
Prior service credit	$	-	$	(20	)	$	(9	)	$	-	$	(9	)	$	(20	)
Net loss		61		60			210			30		271			90
Total	$	61	$	40		$	201		$	30	$	262		$	70

Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block]

	Net Regulatory Asset					Accumulated OCI					Total
In millions	Pension plans		Welfare plans			Pension plans			Welfare plans		Pension plans			Welfare plans
Amortization of prior service credit	$	-	$	(3	)	$	(2	)	$	-	$	(2	)	$	(3	)
Amortization of net loss		9		3			20			2		29			5

Schedule of Expected Benefit Payments [Table Text Block]

In millions	Pension plans		Welfare plans
2015	$	61	$	19
2016		64		20
2017		67		20
2018		70		21
2019		72		22
2020-2024		374		115