Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	6 Months Ended
	Jan. 26, 2023	Apr. 22, 2021	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Shares				6,200,000		6,300,000
Treasury stock, Cost basis				$ 235.4		$ 238.6
Shares repurchased			804,368		1,154,368
2018 Stock Buyback Program [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized for repurchase	4,300,000	4,300,000
Stock repurchase expiration date	Dec. 31, 2024	Dec. 31, 2022
2018 Stock Buyback Program [Member] | Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Shares repurchased				1,700,000	1,154,368
Shares purchased average cost per share				$ 48.77	$ 48.93
Restricted Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares nonvested				600,000		700,000