Common Stock Repurchase Programs - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	May 31, 2018
Share Repurchases [Line Items]
Repurchased	$ 200,000,000	$ 299,504,000
May 2018 Repurchase Program
Share Repurchases [Line Items]
Value of repurchased common stock						$ 600,000,000.0
Accelerated share repurchase (shares)			0.8	0.1
Share repurchase price (in dollars per share)			$ 264.93	$ 356.54
Repurchased			$ 200,000,000.0	$ 50,000,000.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount					$ 100,000,000.0
2018 ASR
Share Repurchases [Line Items]
Accelerated share repurchase (shares)				0.2
Share repurchase price (in dollars per share)				$ 213.18
Repurchased				$ 50,000,000.0
2019 ASR
Share Repurchases [Line Items]
Accelerated share repurchase (shares)			1.1
Share repurchase price (in dollars per share)			$ 176.61
Repurchased			$ 200,000,000.0