Stockholders' equity - ASR - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended		3 Months Ended			9 Months Ended
	Sep. 09, 2021	May 03, 2021	May 27, 2020	Jan. 30, 2020	Sep. 30, 2021		Sep. 30, 2020	Sep. 30, 2021		Sep. 30, 2020	[3]	Jun. 30, 2020
Stockholders Equity Note
Common stock purchases					$ 264	[1]	$ 185	$ 355,571	[2]	$ 503,667
Treasury stock
Stockholders Equity Note
Common stock purchases					61,707	[1]	185	347,014	[2]	580,003
Capital surplus
Stockholders Equity Note
Common stock purchases					(61,443)	[1]	$ 0	$ 8,557	[2]	$ (76,336)
Accelerate share repurchase
Stockholders Equity Note
Stock Repurchased During Period Shares			11,819,135
Stock repurchase program authorized amount		$ 350,000		$ 500,000
Accelerated share repurchases price paid per share	$ 75.8430		$ 42.3043					$ 75.84
Accelerated share repurchases settlement receipt					$ 350,000			$ 350,000				$ 500,000
Initial shares received as part of an accelerated share repurchase program		3,785,831		7,055,919
Common Shares Repurchased Accelerated Share Repurchase Agreements	828,965
Common shares attributable to ASR	4,614,796
Accelerate share repurchase | Treasury stock
Stockholders Equity Note
Common stock purchases	$ 61,000	$ 280,000		$ 400,000
Accelerate share repurchase | Capital surplus
Stockholders Equity Note
Common stock purchases		$ (70,000)		$ (100,000)
Accelerate share repurchase | COVID 19
Stockholders Equity Note
Common Shares Repurchased Accelerated Share Repurchase Agreements			4,763,216

[1] During the quarter ended September 30, 2021, the Corporation completed its previously announced $350 million accelerated share repurchase transaction with respect to its common stock. Refer to Note 17 for additional information.

[2] During the quarter ended June 30, 2021, the Corporation entered into a $350 million accelerated share repurchase transaction with respect to its common stock, which was accounted for as a treasury stock transaction. The transaction was completed on September 9, 2021. Refer to Note 17 for additional information.

[3] During the quarter ended June 30, 2020, the Corporation completed a $500 million accelerated share repurchase transaction with respect to its common stock, which was accounted for as a treasury stock transaction. Refer to Note 17 for additional information.