Stock-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock Option Activity

Information related to stock options issued to officers, other employees and directors under all plans is presented in the following table:

	2017			2016				2015
	Shares	Weighted Average Exercise Price		Shares		Weighted Average Exercise Price		Shares		Weighted Average Exercise Price
Number of shares under option:
Outstanding — beginning of year	—	$	—	84,261		$	17.42	97,962		$	16.61
Granted	114,943	48.63		—		—		—		—
Exercised	—	—		(84,261	)	17.42		(13,701	)	11.66
Canceled	—	—		—		—		—		—
Outstanding — end of year	114,943	$	48.63	—		$	—	84,261		$	17.42
Exercisable — end of year	—	$	—	—		$	—	84,261		$	17.42

Schedule of Stock-Based Compensation

We recorded stock-based compensation for Restricted Shares as follows:

	Year Ended December 31,
	2017			2016		2015
	(Amounts in millions)
Stock-based compensation expense	$	22.8		$	30.2	$	34.8
Related income tax benefit	(5.2		)	(10.4)		(11.8)
Net stock-based compensation expense	$	17.6		$	19.8	$	23.0

Information Regarding Restricted Shares

The following table summarizes information regarding Restricted Shares:

	Year Ended December 31, 2017
	Shares		Weighted Average Grant-Date Fair Value
Number of unvested Restricted Shares:
Outstanding — beginning of year	1,259,275		$	50.77
Granted	692,819		49.20
Vested	(523,529	)	58.28
Canceled	(224,713	)	48.05
Outstanding — ending of year	1,203,852		$	47.10