Share-Based Compensation - Share-Based Compensation and Related Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement [Abstract]
Share-based compensation expense	$ 18,782	$ 11,501	$ 50,550	$ 33,968
Income tax benefit related to share-based compensation expense	$ (4,883)	$ (2,895)	$ (12,028)	$ (7,955)