Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Summary Of Company's Outstanding Restricted Stock Units

A summary of the Company’s outstanding restricted stock units is presented below:



	Shares		Weighted-Average Grant-Date Fair Value
Shares outstanding at December 31, 2014	978,028		$	51.39
Grants	366,200		63.09
Vests	(557,402	)	47.92
Forfeitures and adjustments	(38,007	)	59.63
Shares outstanding at December 31, 2015	748,819		$	59.34

Schedule Of Company's Outstanding Performance Share Units

A summary of the Company’s outstanding performance share units is presented below:



	Performance Share Units		Weighted-Average Grant-Date Fair Value
Performance share units outstanding, December 31, 2014	1,127,088		$	49.63
Grants	355,688		61.82
Vests	(458,755	)	41.68
Performance adjustment (1)	70,140		41.68
Forfeitures and adjustments	(31,242	)	58.90
Performance share units outstanding, December 31, 2015	1,062,919		$	56.37


(1)	Represents the change in shares issued based upon the attainment of performance goals established by the Company.

Schedule Of Estimation Of Fair Value Of Awards



	For awards granted during the year ended December 31,
	2015		2014		2013
Expected volatility	19.06	%	24.66	%	26.76	%
Expected term (years)	2.81		2.80		2.80
Risk free interest rate	0.99	%	0.66	%	0.39	%

Schedule of Share-based Payment Award, ESPP, Valuation Assumptions

The fair value of each award under the ESPP was estimated at the beginning of each offering period using the Black-Scholes option-pricing model and assumptions in the table below. Expected volatilities are based on implied volatilities from traded options on the Company’s stock and the historical volatility of the Company’s stock. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The dividend yield is based on the current annualized dividend and share price as of the grant date.



	For awards issued during the year ended December 31,
	2015	2014	2013
Expected volatility	16.79 - 17.67%	19.02 - 20.65%	18.30 - 25.40%
Risk free interest rates	0.06 - 0.11%	0.09%	0.08 - 0.15%
Dividend yield	1.58 - 1.62%	1.52 - 1.92%	2.34 - 2.38%
Expected term (years)	0.5	0.5	0.5