Stock Options And Restricted Stock Awards (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Granted shares	0
Stock option compensation expense	$ 0.9	$ 1.2	$ 1.4
Unrecognized compensation cost	$ 1.0
Unrecognized compensation cost recognition period	2 years
Intrinsic value on exercisable stock options	$ 21.0
Intrinsic value on outstanding stock options	$ 21.2
Share-based compensation number of shares vested	415,000
Share-based compensation number of shares unvested	40,000
Intrinsic value on exercised stock options	$ 0.8	3.5	1.8
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option compensation expense	9.4	$ 9.4	$ 8.0
Unrecognized compensation cost	$ 10.4
Unrecognized compensation cost recognition period	1 year 4 months 24 days
Fair market value of vested restricted stock awards	$ 9.9
A&R 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum shares of stock awards authorized for issuance	864,215
Share-based compensation number of common stock available for grant	854,003
Number of shares newly Authorized	590,000
Number of shares available for issuance Shares	274,215
A&R 2017 Plan | Stock options or SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum shares of stock awards authorized for issuance	500,000
A&R 2017 Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award, expiration period	10 years
Exercise prices of stock options outstanding, lower range limit	$ 19.71
Exercise prices of stock options outstanding, upper range limit	$ 92.00
A&R 2017 Plan | Employee Stock Option | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment vesting period	3 years
A&R 2017 Plan | Employee Stock Option | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment vesting period	4 years
A&R 2017 Plan | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award, expiration period	10 years
A&R 2017 Plan | Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment vesting period	1 year
A&R 2017 Plan | Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment vesting period	4 years