Share-Based Compensation and Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2019

Dec. 31, 2018

Share-based Payment Arrangement, Noncash Expense [Abstract]

Summary Of Share Incentive Plans

A summary of activity under our share incentive plans for the year ended December 31, 2019 is shown below:

	Nonvested Share Awards Outstanding		Weighted Average Exercise  / Grant Price
Nonvested share awards outstanding at December 31, 2018	390,681		$	79.82
Granted	199,957		98.84
Exercised/Vested	(308,514	)	82.65
Forfeited	(17,470	)	86.64
Total nonvested share awards outstanding at December 31, 2019	264,654		$	90.44

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The weighted-average fair value of reload stock options granted during the years ended December 31, 2018 and 2017 and the weighted-average assumptions for such grants were as follows:

	Year Ended December 31, 2018	Year Ended December 31, 2017
Weighted average fair value of options granted	$4.11	$5.25
Expected volatility	15.1%	18.9%
Risk-free interest rate	2.0%	1.3%
Expected dividend yield	3.3%	5.5%
Expected life	1 year	2 years

Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity [Table Text Block]

The following table presents information related to our ESPP:

	2019		2018		2017
Shares purchased	22,032		15,330		18,986
Weighted average fair value of shares purchased	$	105.93	$	90.93	$	89.89
Expense recorded (in millions)	$	0.4	$	0.2	$	0.3

Temporary Equity [Table Text Block]

The following table summarizes the eligible share award activity for the years ended December 31, 2018 and 2017:

(in thousands)	2018			2017
Temporary equity:
Balance at beginning of period	$	77,230		$	77,037
Change in classification	16,407			13,388
Change in redemption value	(669		)	10,038
Diversification of share awards (429 shares during December 31, 2018)	(40,294		)	(23,233		)
Balance at December 31	$	52,674		$	77,230