SHARE-BASED AWARDS (Tables)

12 Months Ended

Dec. 31, 2018

Summary of Compensation expense and Other Measures Related to Share-Based awards


	Years Ended December 31,
Share-based compensation expense, net of estimated forfeitures (in millions)	2018		2017		2016
Share-based compensation expense	$	12.1	$	11.1	$	9.8
Intrinsic value of options exercised	$	0.5	$	0.7	$	2.0
Tax benefit realized upon stock vesting	$	2.7	$	6.8	$	5.9
Fair value of stock vested	$	10.8	$	17.3	$	15.8

Stock Option Activity

Activity in the Company’s stock option plans for the year ended December 31, 2018, was as follows (in thousands, except weighted average exercise price and weighted average contractual life):


		Weighted		Weighted
		Average		Average	Aggregate
	2007 Plan	Exercise		Contractual	Intrinsic
	Shares	Price		Life	Value
Outstanding at December 31, 2017	235	$	21.54
Exercised	(39)	$	20.18
Outstanding at December 31, 2018	196	$	21.81	2.6	$	1,998
Exercisable at December 31, 2018	196	$	21.81	2.6	$	1,998

Non-Vested Restricted Stock Unit Activity

The following table summarizes non-vested restricted stock unit activity through December 31, 2018, (in thousands, except weighted average grant-date fair value amounts):


	2007 Plan	2016 Plan	Total	Weighted
	Restricted	Restricted	Restricted	Average Grant-
	Stock Units	Stock Units	Stock Units	Date Fair Value
Outstanding at December 31, 2017	377	309	686	$	36.41
Granted	—	384	384	$	31.15
Settlement of Performance Shares (1)	60	—	60	$	36.97
Vested	(268)	(78)	(346)	$	36.24
Canceled	(5)	(20)	(25)	$	34.49
Outstanding at December 31, 2018	164	595	759	$	33.92