Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Oct. 31, 2018	May 24, 2018
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares of common stock subject to awards					1,500,000
Shares available for grant	821,703	1,032,403	1,195,993
Weighted average diluted shares outstanding excludes shares of common stock subject to stock options	165,000	102,000	119,000
Number of shares authorized to be repurchased (in shares)				200,000,000
Stock repurchase program, period in force	3 years
Stock repurchased during period (in shares)	253,490	253,490
Weighted average price (in usd per share)	$ 94.89
Stock repurchased during period	$ 24.1
Deferred and Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award
Unrecognized compensation costs	$ 18.9
Unrecognized compensation costs, weighted-average recognition period	1 year 3 months 18 days
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Unrecognized compensation costs	$ 0.6
Unrecognized compensation costs, weighted-average recognition period	2 months 12 days