Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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Stockholders' Equity - Schedule of Stock Repurchases (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Stockholders Equity [Line Items]
Total cost		$ 46,133	$ 82,866	$ 51,053	$ 50,311
2016 Stock Repurchase Program
Stockholders Equity [Line Items]
Shares of common stock repurchased and retired (in shares)	0		749			422	1,670
Average price paid per share (in dollars per share)	$ 0		$ 110.57			$ 109.37	$ 110.27
Total cost	$ 0		$ 82,852			$ 46,124	$ 184,196