Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Summary of Stock Based Compensation Activity Related to Nonvested RSUs

The following table summarizes activity related to nonvested RSUs:

	Number of RSUs (In thousands)	Weighted Average Grant-Date Fair Value Per Share
Nonvested at December 31, 2017	651	$	220.21
Granted	406	353.99
Vested	(470)	271.50
Forfeited	(24)	282.07
Nonvested at December 31, 2018	563	$	271.23
Granted	581	305.30
Vested	(523)	269.00
Forfeited	(21)	302.78
Nonvested at December 31, 2019	600	$	305.06
Granted	533	383.99
Vested	(383)	329.63
Forfeited	(17)	349.02
Nonvested at December 31, 2020	733	$	348.60