Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Employee Stock Purchase Plan

Following is information regarding our 2009 ESPP:

Year Ended December 31,	2019
Shares purchased pursuant to 2009 ESPP	112,138
Weighted average per share price of shares purchased	$	101.03
Weighted average per share discount from market value for shares purchased	$	17.83
As of December 31,	2019
Shares available for purchase pursuant to 2009 ESPP	1,526,505

Schedule of Restricted Stock Units Activity

RSU grants vest over a period of time up to four years from the date of grant. RSU activity was as follows:

	RSUs		Weighted average grant date fair value
Balance, December 31, 2018	409,865		$	99.72
Granted	288,761		75.73
Vested	(117,873	)	92.00
Forfeited	(84,071	)	87.53
Balance, December 31, 2019	496,682		90.00

Schedule of Stock-Based Compensation

Certain information regarding our stock-based compensation was as follows:

Year Ended December 31,	2019		2018		2017
Per share intrinsic value of non-vested stock granted	$	75.73	$	86.84	$	99.24
Weighted average per share discount for compensation expense recognized under the 2009 ESPP	17.83		13.10		15.20
Fair value of non-vested stock that vested during the period (in millions)	92.0		92.0		69.6
Stock-based compensation recognized in Consolidated Statements of Operations, as a component of selling, general and administrative expense (in millions)	16.2		13.4		11.3
Tax benefit recognized in Consolidated Statements of Operations (in millions)	2.7		3.5		3.5
Cash received from options exercised and shares purchased under all share-based arrangements (in millions)	11.3		10.6		7.8
Tax deduction realized related to stock options exercised (in millions)	9.8		9.0		9.0