Changes in Equity (Detail) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Class of Stock [Line Items]
Beginning Balance			$ 2,271.1
Comprehensive income:
Net income	196.8	206.6	370.7	373.6
Other comprehensive income			93.4
Total comprehensive income	222.1	131.2	464.1	226.6
Stock-based compensation			7.2
Dividends declared			(57.9)
Adjustment to redeemable stock- based awards			(3.3)
Shares issued upon exercise of stock options and awards			9.1
Tax benefit from stock compensation			11.7
Shares purchased upon exercise of stock options and awards			(7.2)
Other - net			0.7
Ending Balance	2,695.5		2,695.5
Common Shares
Class of Stock [Line Items]
Beginning Balance (in shares)			64.0
Beginning Balance			813.6
Comprehensive income:
Stock-based compensation			7.2
Shares issued upon exercise of stock options and awards (in shares)			0.5
Shares issued upon exercise of stock options and awards			9.1
Tax benefit from stock compensation			11.7
Shares purchased upon exercise of stock options and awards (in shares)			(0.1)
Shares purchased upon exercise of stock options and awards			(0.8)
Other - net			0.7
Ending Balance (in shares)	64.4		64.4
Ending Balance	841.5		841.5
Retained Earnings
Class of Stock [Line Items]
Beginning Balance			1,517.4
Comprehensive income:
Net income			360.8
Dividends declared			(46.5)
Adjustment to redeemable stock- based awards			(3.3)
Shares purchased upon exercise of stock options and awards			(6.4)
Ending Balance	1,822.0		1,822.0
Accumulated Other Comprehensive (Loss) Income
Class of Stock [Line Items]
Beginning Balance			(137.5)
Comprehensive income:
Other comprehensive income			92.9
Ending Balance	(44.6)		(44.6)
Noncontrolling Interests
Class of Stock [Line Items]
Beginning Balance			77.6
Comprehensive income:
Net income			9.9
Other comprehensive income			0.5
Dividends declared			(11.4)
Ending Balance	$ 76.6		$ 76.6