EARNINGS PER SHARE CALCULATIONS. (Detail) (USD $) In Millions, except Per Share data	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Earnings Per Share Calculations [Abstract]
Net income	$ 204.7	$ 158.5	$ 399.3	$ 311.5
Less: net income allocated to outstanding restricted stock and stock unit holders	(0.9)	(0.7)	(1.7)	(1.3)
Net income allocated to common stockholders (basic)	203.8	157.8	397.6	310.2
Net income allocated to common stockholders (diluted)	$ 203.8	$ 157.8	$ 397.6	$ 310.2
Weighted average common shares
Outstanding (shares)	258.0	258.2	258.3	258.2
Outstanding assuming dilution (shares)	266.7	265.7	267.6	266.0
Weighted average outstanding stock options excluded (options)	3.6	12.9	2.6	12.2
Average exercise price (in dollars per option)	$ 67.61	$ 52.39	$ 67.92	$ 52.55

The weighted average exercise price of securities that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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