Note 7 - Stock-Based Compensation (Detail) - Stock Option Activity (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2010 Beginning Of Period [Member]	Dec. 31, 2009 Beginning Of Period [Member]	Dec. 31, 2010 End Of Period [Member]
Outstanding	1,823,154				2,551,568	2,229,112
Outstanding - weighted average exercise price (in Dollars per share)	$ 36.09	$ 35.61		$ 34.48		$ 34.85
Outstanding - weighted average remaining life	3 years 255 days	4 years 219 days
Outstanding - aggregate intrinsic value (in Dollars)	$ 6
Exercisable	1,528,590	1,747,656	1,799,334
Exercisable - weighted average exercise price (in Dollars per share)	$ 36.09	$ 35.81	$ 34.92
Exercisable - weighted average remaining life	3 years 255 days	4 years 6 months	4 years 328 days
Exercisable - aggregate intrinsic value (in Dollars)	$ 6	$ 11	$ 4
Granted	0	1,685	0
Granted - weighted average exercise price (in Dollars per share)	$ 0	$ 42.19	$ 0
Granted - weighted average remaining life	0 years
Exercised	(234,844)	(383,646)	(296,008)
Exercised - weighted average exercise price (in Dollars per share)	$ 32.07	$ 31.11	$ 31.33
Exercised - weighted average remaining life	3 years 73 days
Forfeited	(59,720)	(23,997)	(26,448)
Forfeited - weighted average exercise price (in Dollars per share)	$ 37.34	$ 37.70	$ 37.85
Forfeited - weighted average remaining life	4 years
Outstanding	1,528,590	1,823,154			2,551,568	2,229,112