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Stockholders' Equity (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	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	1,195,993	1,300,115	1,361,748
Weighted average diluted shares outstanding excludes shares of common stock subject to stock options	119,000	111,000	123,000
Number of shares authorized to be repurchased (in shares)				150,000,000
Stock repurchase program, period in force	3 years
Deferred and Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award
Unrecognized compensation costs	$ 16.1
Unrecognized compensation costs, weighted-average recognition period	1 year 3 months 18 days
Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award
Unrecognized compensation costs	$ 12.0
Unrecognized compensation costs, weighted-average recognition period	10 months 24 days