Compensation Plans (Schedule of Assumptions Used in Determining Fair Value of Stock Options) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Compensation Plans [Abstract]
Dividend yield	3.20%	3.20%	4.90%
Volatility	34.87%	33.26%	32.44%
Risk-free interest rate	0.90%	2.30%	2.60%
Expected life (years)	5 years 3 months 18 days	5 years 3 months 18 days	5 years 3 months 18 days