Share-Based Compensation Tables (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement, Noncash Expense [Abstract]

Schedule Of Share-based Compensation Costs Related To Unvested Restricted Stock [Table Text Block]

The remaining share-based compensation cost, net related to our unvested restricted shares outstanding as of December 31, 2019 is approximately $39.0 million. The following table summarizes our expected share-based compensation cost, net related to our unvested restricted shares, in millions:



	2020		2021		2022		Thereafter
Expected share-based compensation costs, net	$	16.6	$	11.3	$	7.1	$	4.0

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

The following table summarizes our restricted stock activity for the years ended December 31, 2019, 2018, and 2017:



	Number of Shares		Weighted Average Grant Date Fair Value
Unvested restricted shares at January 1, 2017	841,634		$	56.38
Granted	219,400		$	79.38
Vested	(196,412	)	$	47.60
Forfeited	(4,769	)	$	56.43
Unvested restricted shares at December 31, 2017	859,853		$	64.25
Granted	233,400		$	87.12
Vested	(214,111	)	$	54.69
Forfeited	(8,025	)	$	72.16
Unvested restricted shares at December 31, 2018	871,117		$	72.65
Granted	190,020		$	117.47
Vested	(237,406	)	$	64.46
Forfeited	(10,690	)	$	79.58
Unvested restricted shares at December 31, 2019	813,041		$	85.43

During the year ended December 31, 2019 and 2018, shares were granted as follows:



Grant Period	Type	Plan	Shares Granted		Grant Date Fair Value Per Share			Vesting Type	Vesting Anniversary	Percentage
2019	Executive Officers	2015 Equity Incentive Plan	44,000		$	115.39	⁽¹⁾	Time Based	20.0% annually over 5 years
2019	Executive Officers	2015 Equity Incentive Plan	66,000	⁽²⁾	$	115.39	⁽²⁾	Market Condition	3rd	100.0	%
2019	Directors	2004 Non-Employee Director Option Plan	18,000		$	113.68	⁽¹⁾	Time Based	3rd	100.0	%
2019	Key Employees	2015 Equity Incentive Plan	55,770		$	120.01	⁽¹⁾	Time Based	20.0% annually over 5 years
2019	Key Employees	2015 Equity Incentive Plan	6,250		$	142.48	⁽¹⁾	Time Based	20.0% annually over 5 years
2018	Key Employees	2015 Equity Incentive Plan	16,500		$	88.30	⁽¹⁾	Time Based	2nd	35.0	%
									3rd	35.0	%
									4th	20.0	%
									5th	5.0	%
									6th	5.0	%
2018	Key Employees	2015 Equity Incentive Plan	50,100		$	86.97	⁽¹⁾	Time Based	20.0% annually over 5 years
2018	Executive Officers	2015 Equity Incentive Plan	60,000		$	87.24	⁽¹⁾	Time Based	20.0% annually over 5 years
2018	Executive Officers	2015 Equity Incentive Plan	90,000		$	65.24	⁽³⁾	Market Condition	3rd	100.0	%
2018	Directors	2004 Non-Employee Director Option Plan	16,800		$	85.28	⁽¹⁾	Time Based	3rd	100.0	%

⁽¹⁾ Grant date fair value is measured based on the closing price of our common stock on the date(s) shares are issued.

⁽²⁾ Share-based compensation for restricted stock awards with market and performance conditions is measured based on an estimate of shares expected to vest. We estimate the fair value of share-based compensation for restricted stock with market conditions using a Monte Carlo simulation. At the grant date, our common stock price was $115.39. Based on the Monte Carlo simulation we expect 75.1% of the 66,000 shares to vest.

⁽³⁾ Share-based compensation for restricted stock awards with market conditions is measured based on an estimate of shares expected to vest. We estimate the fair value of share-based compensation for restricted stock with market conditions using a Monte Carlo simulation. At the grant date, our common stock price was $87.24. Based on the Monte Carlo simulation we expect 74.8% of the 90,000 shares to vest.