Share repurchases (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 28, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Nov. 04, 2019
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock (in shares)		8,232	30,592	12,284	32,652
Value of treasury stock acquired		$ 725,439	$ 1,747,968	$ 1,028,578	$ 1,860,157
Treasury stock acquired, average cost per share		$ 88.13	$ 57.14	$ 83.73	$ 56.97
Terminated Remaining Prior Share Repurchases Authorized, Amount						$ 246,373
Stock Repurchase Program, Authorized Amount						$ 2,000,000
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock (in shares)	1,828
Value of treasury stock acquired	$ 160,783
Treasury stock acquired, average cost per share	$ 87.96
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 515,926
Tender Offer
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock (in shares)		7,982	21,802	7,982	21,802
Value of treasury stock acquired		$ 704,180	$ 1,233,886	$ 704,180	$ 1,233,886
Treasury stock acquired, average cost per share		$ 88.22	$ 56.60	$ 88.22	$ 56.60