Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement, Noncash Expense [Abstract]

Target grants performance share

Target grants of performance shares outstanding at December 31, 2019, were as follows:

Grant Date	Performance Period	Target Grant of Shares
February 2018	2018-2020	246,309
February 2019	2019-2021	327,194

Schedule of share-based payment award, performance shares, valuation assumptions

Assumptions used for grants applicable to the market condition for certain performance shares issued in 2019, 2018 and 2017 were:

				2019						2018						2017
Weighted average grant-date fair value					$35.07						$34.55						$24.31
Blended volatility range	19.50	%	–	19.69		%	17.87	%	–	22.14		%	22.70	%	–	25.56		%
Risk-free interest rate range	2.46	%	–	2.55		%	1.86	%	–	2.46		%	.69	%	–	1.61		%
Weighted average discounted dividends per share					$2.85						$2.46						$1.70

Summary of the status of the performance share awards

A summary of the status of the performance share awards for the year ended December 31, 2019, was as follows:

	Number of Shares	Weighted Average Grant-Date Fair Value
Nonvested at beginning of period	668,791	$	23.03
Granted	327,194	30.66
Additional performance shares earned	103,159	14.60
Less:
Vested	398,919	15.52
Forfeited	126,722	24.31
Nonvested at end of period	573,503	$	30.81