Note 7 - Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

In millions	2012		2011		2010
Compensation costs (1)	$	9	$	14	$	11
Income tax benefits (1)		1		1		2
Excess tax benefits (2)		1		1		2

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of options			Weighted average exercise price		Weighted average remaining life (in years)		Aggregate intrinsic value (in millions)
Outstanding - December 31, 2009		2,551,568		$	34.48
Granted		0			0
Exercised		(296,008	)		31.33
Forfeited		(26,448	)		37.85
Outstanding - December 31, 2010		2,229,112		$	34.85
Granted		1,685			42.19
Exercised		(383,646	)		31.11
Forfeited		(23,997	)		37.70
Outstanding - December 31, 2011		1,823,154		$	35.61		4.6
Granted		0			0		0.0
Exercised		(234,844	)		32.07		3.2
Forfeited		(59,720	)		37.34		4.0
Outstanding - December 31, 2012		1,528,590		$	36.09		3.7	$	6
Exercisable - December 31, 2012		1,528,590		$	36.09		3.7	$	6
Exercisable - December 31, 2011		1,747,656		$	35.81		4.5	$	11
Exercisable - December 31, 2010		1,799,334		$	34.92		4.9	$	4

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

	Options exercisable and outstanding
Range of Exercise Prices	Number of options		Weighted average remaining contractual life (in years)		Weighted average exercise price
$26.31 to $30.69		38,500		0.6		26.86
$30.70 to $35.08		335,048		3.9		32.25
$35.09 to $39.46		1,115,866		3.7		37.38
$39.47 to $43.85		39,176		3.9		41.25
Outstanding		1,528,590		3.7	$	36.09

Schedule of Nonvested Performance-based Units Activity [Table Text Block]

In millions	Measurement period end date	Accrued at Dec. 31, 2012		Maximum aggregate payout
Granted in 2011	Dec. 31, 2013	$	4	$	11
Granted in 2012	Dec. 31, 2014	$	3	$	16

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

	Shares of restricted stock			Weighted average remaining vesting period (in years)		Weighted average fair value
Outstanding - December 31, 2010 (1)		400,900				$	30.80
Issued		311,600					39.48
Forfeited		(25,784	)				36.22
Vested		(209,362	)				34.68
Outstanding - December 31, 2011 (1) (2)		477,354			2.6	$	34.40
Issued		268,840			3.0		40.08
Forfeited		(28,829	)		2.0		39.07
Vested		(214,274	)		0.0		36.45
Outstanding - December 31, 2012 (1) (2)		503,091			1.8	$	39.44

Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity [Table Text Block]

	2012		2011		2010
Shares purchased on the open market		108,132		65,843		60,017
Average per-share purchase price	$	38.96	$	40.55	$	37.07
Total purchase price discount	$	618,278	$	401,346	$	333,639