Capital Stock (Share Repurchase Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended		57 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023
Capital Stock
Number of Shares (in shares)	989,792	1,118,457	12,196,627
Average Repurchase Price per Share (in dollars per share)	$ 124.78		$ 90.98
Amount (in thousands)	$ 123,508	$ 158,790	$ 1,109,700
Stock Repurchase Program, remaining amount	$ 217,700		$ 217,700