Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies

Fair value of stock options has been estimated at the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	2012		2011		2010
Risk free interest rate	0.8	%	1.7	%	2.2	%
Expected life	4.6 years		4.6 years		5.6 years
Expected volatility	30.0	%	28.0	%	33.0	%
Expected dividend yield	0.8	%	0.1	%	0.1	%