STATEMENTS OF CONSOLIDATED SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Other Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2018	$ 3,730.7	$ 118.4	$ 2,896.4	$ 6,246.5	$ (4,900.7)	$ (629.9)
Shareholders' Equity [Roll Forward]
Net income	245.2			245.2
Other comprehensive income (loss)	6.0					6.0
Treasury stock purchased	(305.1)				(305.1)
Treasury stock transferred from defined benefit pension plan	(131.8)				(131.8)
Stock-based compensation activity	26.6	0.3	47.6		(21.3)
Other adjustments	1.7		1.6	0.1
Cash dividends	(104.8)			(104.8)
Ending balance at Mar. 31, 2019	3,460.1	118.7	2,945.6	6,386.9	(5,358.9)	(632.2)
Beginning balance at Dec. 31, 2019	4,123.3	119.4	3,153.0	7,366.9	(5,836.5)	(679.5)
Shareholders' Equity [Roll Forward]
Net income	321.7			321.7
Other comprehensive income (loss)	(221.6)					(221.6)
Treasury stock purchased	(890.3)				(890.3)
Treasury stock issued	57.4		13.5		43.9
Stock-based compensation activity	24.2	0.3	48.7		(24.8)
Other adjustments	0.3		0.3
Cash dividends	(122.9)			(122.9)
Ending balance at Mar. 31, 2020	$ 3,289.1	$ 119.7	$ 3,215.5	$ 7,562.7	$ (6,707.7)	$ (901.1)