Financial Information and Accounting Policies - Adjusted Cash Flows to Apply Adopted Guidance (Details) - USD ($) $ in Millions		3 Months Ended						9 Months Ended
		Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)		$ 118.3	$ 131.2	$ 211.6	$ 162.2	$ 205.0	$ 185.1	$ 461.1	$ 552.3
Income (loss) from continuing operations		134.5			171.9			503.3	584.7
Adjustments from income (loss) from continuing operations to cash provided (required) by operating activities of continuing operations:
Deferred income taxes								10.0	9.2
Pension and other postretirement benefits								9.4	7.6
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Inventories								(282.3)	(367.4)
Income taxes								(3.5)	(22.0)
Change in other operating assets and liabilities, net	[1]							(21.3)	(49.2)
Net cash provided (required) by operating activities of continuing operations								15.7	298.2
As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)		113.9			160.4			456.7	546.8
Income (loss) from continuing operations		130.1			170.1			498.9	579.2
Adjustments from income (loss) from continuing operations to cash provided (required) by operating activities of continuing operations:
Pension and other postretirement benefits								15.0	18.4
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Inventories								(282.3)	(371.2)
Income taxes								(4.7)	(23.5)
Net cash provided (required) by operating activities of continuing operations								15.7	298.2
Effect of Change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)		4.4						4.4
Income (loss) from continuing operations		$ 4.4						4.4
Adjustments from income (loss) from continuing operations to cash provided (required) by operating activities of continuing operations:
Pension and other postretirement benefits								(5.6)
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Inventories								0.0
Income taxes								1.2
Net cash provided (required) by operating activities of continuing operations								$ 0.0
Effect of Change | Combined Effect of Changes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)					1.8				5.5
Income (loss) from continuing operations					1.8				5.5
Adjustments from income (loss) from continuing operations to cash provided (required) by operating activities of continuing operations:
Pension and other postretirement benefits									(10.8)
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Inventories									3.8
Income taxes									1.5
Net cash provided (required) by operating activities of continuing operations									0.0
Effect of Change | Effect of FIFO Change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)					(1.0)				(3.0)
Income (loss) from continuing operations					(1.0)				(3.0)
Adjustments from income (loss) from continuing operations to cash provided (required) by operating activities of continuing operations:
Pension and other postretirement benefits									0.0
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Inventories									3.8
Income taxes									(0.8)
Net cash provided (required) by operating activities of continuing operations									0.0
Effect of Change | Effect of Pension Change
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)					2.8				8.5
Income (loss) from continuing operations					$ 2.8				8.5
Adjustments from income (loss) from continuing operations to cash provided (required) by operating activities of continuing operations:
Pension and other postretirement benefits									(10.8)
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Inventories									0.0
Income taxes									2.3
Net cash provided (required) by operating activities of continuing operations									$ 0.0

[1] Changes in all periods primarily represent timing of payments associated with all other operating assets and liabilities.