Capital Stock, Repurchases of Common Stock (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jul. 31, 2018
Repurchases of Common Stock [Abstract]
Class A common stock repurchased	$ 80,420	$ 144,334	$ 825
2018 Stock Repurchase Plan [Member]
Repurchases of Common Stock [Abstract]
Authorized amount				$ 500,000
Amount available for repurchases	245,400
Treasury Stock [Member]
Repurchases of Common Stock [Abstract]
Class A common stock repurchased	$ 80,420	$ 144,334	$ 825
Treasury Stock [Member] | 2018 Stock Repurchase Plan [Member]
Repurchases of Common Stock [Abstract]
Class A common stock repurchased (in shares)	1,600,000	5,100,000	14,000
Class A common stock repurchased	$ 80,400	$ 144,300	$ 800