Equity Based Compensation Plans Weighted average assumptions (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Weighted average assumptions used to estimate fair value of stock options [Abstract]
Stock price (in dollars per share)	$ 153.54	$ 143.95	$ 131.87
Risk-free interest rates (in hundredths)	2.68%	1.16%	2.23%
Expected lives	10 years		10 years
Volatility (in hundredths)	18.03%	20.05%	19.63%
Dividend yield (in hundredths)	3.15%	3.26%	3.29%
Minimum [Member]
Weighted average assumptions used to estimate fair value of stock options [Abstract]
Expected lives		5 years
Maximum [Member]
Weighted average assumptions used to estimate fair value of stock options [Abstract]
Expected lives		10 years