Share-Based Compensation (Estimate Fair Value Of Share-Based Awards With Weighted-Average Assumptions) (Detail) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Total Options Outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	2.30%	2.20%
Expected volatility	33.60%	31.70%
Risk-free interest rate	3.00%	3.60%
Expected term (in years)	5 years 8 months	6 years 4 months
Weighted-average grant-date fair value	$ 13.57	$ 16.41
Options Granted During The Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	2.60%	2.40%
Expected volatility	41.00%	35.40%
Risk-free interest rate	0.90%	1.50%
Expected term (in years)	5 years	5 years
Weighted-average grant-date fair value	$ 14.74	$ 12.84