Subsequent Events (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Apr. 22, 2019
Subsequent Event [Line Items]
Shares repurchased (in shares)	8,088,147
Shares repurchased, average share price (in USD per share)	$ 81.86
Shares repurchased, aggregate purchase price	$ 662,100,000
Amount remaining under existing authorization	$ 388,000,000
Subsequent Event
Subsequent Event [Line Items]
Incremental increase to share repurchase program		$ 300,000,000
Share repurchase program, total authorization		$ 1,050,000,000.00