Stock Based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Changes in option shares, all of which relate to the Company’s Common Stock, were as follows for the three months ended March 31, 2017:


	Weighted-Avg. Per Share Exercise Price		Number of Options			Average Remaining Contractual Life		Aggregate Intrinsic Value (dollars in millions)
Outstanding at January 1, 2017	$	21.69		2,664,333
Granted		50.16		358,150
Exercised		23.32		(222,192	)
Terminated		31.39		(1,360	)

Outstanding at March 31, 2017		25.19		2,798,931			8 years	$	72.7

Exercisable at March 31, 2017		18.68		1,911,832			7 years	$	62.1

Schedule of Weighted Average Fair Value per Option at Date of Grant

The weighted-average fair value per option at the date of grant during the three months ended March 31, 2017 and 2016 using the Black-Scholes option-pricing model was $13.04 and $7.89, respectively. Assumptions were as follows:


	Three Months Ended March 31,
	2017			2016
Expected life (years)		5.7			5.8
Risk-free interest rate		2.4	%		1.7	%
Dividend yield		1.0	%		1.3	%
Expected volatility		26.5	%		27.8	%

Schedule of Share Unit Activity Under Plan

A summary of share unit activity under the plan is as follows for the three months ended March 31, 2017:


	Number of Units			Weighted-Average Grant Date Value
Issued and unvested at January 1, 2017		544,055		$	27.35
Granted		107,755			50.16
Vested		(213,273	)		23.24
Forfeited		(2,060	)		31.22

Issued and unvested at March 31, 2017		436,477			34.97