CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2020	$ 3,020.4	$ 292.8	$ (2,255.2)	$ 274.4	$ 4,786.0	$ (77.6)
Beginning Balance (in shares) at Dec. 31, 2020		292,800,000	47,400,000
Net income	220.7	$ 0.0	$ 0.0	0.0	220.7	0.0
Other comprehensive income (loss)	23.0	0.0	0.0	0.0	0.0	23.0
Cash dividends	(61.9)	0.0	0.0	0.0	(61.9)	0.0
Stock purchases	0.0	$ 0.0	$ (30.0)	30.0	0.0	0.0
Stock purchases (in shares)		0.0	(400,000)
Stock based compensation expense and stock option plan transactions	9.0	$ 0.0	$ 7.2	1.8	0.0	0.0
Stock based compensation expense and stock option plan transactions (in shares)		0.0	100,000
Ending Balance at Mar. 31, 2021	3,211.2	$ 292.8	$ (2,278.0)	306.2	4,944.8	(54.6)
Ending Balance (in shares) at Mar. 31, 2021		292,800,000	(47,700,000)
Beginning Balance at Dec. 31, 2021	3,233.2	$ 292.8	$ (2,667.7)	310.3	5,366.0	(68.2)
Beginning Balance (in shares) at Dec. 31, 2021		292,800,000	(50,300,000)
Net income	204.4	$ 0.0	$ 0.0	0.0	204.4	0.0
Other comprehensive income (loss)	15.0	0.0	0.0	0.0	0.0	15.0
Cash dividends	(63.7)	(0.0)	(0.0)	(0.0)	(63.7)	(0.0)
Stock purchases	0.0	$ (0.0)	$ 20.0	(20.0)	(0.0)	(0.0)
Stock purchases (in shares)		(0.0)	200,000
Stock based compensation expense and stock option plan transactions	14.0	$ 0.0	$ 10.1	3.9	0.0	0.0
Stock based compensation expense and stock option plan transactions (in shares)		0.0	300,000
Ending Balance at Mar. 31, 2022	$ 3,402.9	$ 292.8	$ (2,677.6)	$ 334.2	$ 5,506.7	$ (53.2)
Ending Balance (in shares) at Mar. 31, 2022		292,800,000	(50,200,000)