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Certain Employee Benefit and Stock-Based Compensation Plans (Option Pricing Assumptions) (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Share-based Compensation [Abstract]
Risk-free interest rate	1.10%	2.80%
Dividend yield	2.30%	0.60%
Volatility	35.10%	34.70%
Expected life	5.9	5.9
Grant- date fair value	$ 16.22	$ 22.82

The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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