Share-Based Compensation

9 Months Ended

Sep. 30, 2019

Share-based Payment Arrangement [Abstract]

The following table presents share-based compensation expense:



	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2018		2019		2018		2019
Share-based compensation	$	11.7	$	11.7	$	33.5	$	30.7
Tax benefit	2.9		2.0		8.4		6.7

As of December 31, 2018, the Company had unrecognized share-based compensation expense of $54.1 million. As of September 30, 2019, the Company had unrecognized share-based compensation expense of $116.0 million, which will be recognized over a weighted average period of approximately three years (assuming no forfeitures).

Stock Options

The following table summarizes transactions in the Company’s stock options:



	Stock Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)
Unexercised options outstanding - December 31, 2018	0.5		$	130.81
Options granted	1.8		74.91
Options exercised	(0.0	)	79.49
Options forfeited	(0.0)		116.89
Unexercised options outstanding - September 30, 2019	2.3		86.25		6.1
Exercisable at September 30, 2019	0.4		130.15		3.0

For the nine months ended September 30, 2018 and 2019, the Company granted stock options with fair values of $1.0 million and $33.3 million, respectively. Stock options generally vest over a period of three years to five years and expire seven years after the grant date. All stock options have been granted with exercise prices equal to the closing price of the Company’s common stock on the grant date. Substantially all of the Company’s outstanding stock options contain both service and performance conditions. Because of the performance conditions, the number of stock options that the Company delivers upon vesting may be greater than or less than the number of stock options granted. During the nine months ended September 30, 2019, there were no changes in the Company’s estimate of the number of stock options expected to be delivered.

The weighted average fair value of options granted was $48.64 and $18.36, per option, for the nine months ended September 30, 2018 and 2019, respectively. The Company uses the Black-Scholes option pricing model to determine the fair value of options. The weighted average grant date assumptions used to estimate the fair value of options granted were as follows:



	For the Nine Months Ended September 30,
	2018		2019
Dividend yield	0.8	%	0.9	%
Expected volatility	25.5	%	26.2	%
Risk-free interest rate	2.8	%	2.9	%
Expected life of options (in years)	5.7		5.7
Forfeiture rate	—	%	—	%

Restricted Stock

The following table summarizes transactions in the Company’s restricted stock units:



	Restricted Stock Units		Weighted Average Grant Date Value
Unvested units - December 31, 2018	0.6		$	172.74
Units granted	0.6		91.52
Units vested	(0.2	)	168.95
Units forfeited	(0.0	)	143.55
Unvested units - September 30, 2019	1.0		121.11

For the nine months ended September 30, 2018 and 2019, the Company granted restricted stock units with fair values of $37.7 million and $60.6 million, respectively. These restricted stock units were valued based on the closing price of the Company’s common stock on the grant date and the number of shares expected to be delivered. Restricted stock units containing vesting conditions generally require service over a period of three years to four years and may also require the satisfaction of certain performance conditions. Because of the performance conditions, the number of shares of the Company’s common stock that the Company delivers upon vesting may be greater than or less than the number of restricted stock units granted. During the nine months ended September 30, 2019, there were no changes in the Company’s estimate of the number of shares expected to be delivered.