Summary of Significant Accounting Policies - Change In Accounting Principle Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues	$ 1,195.0	$ 1,426.8	$ 1,500.9	$ 1,072.6	$ 5,195.3	$ 5,341.3	$ 4,981.9
Cost of goods sold	805.7	939.6	983.4	731.7	3,460.5	3,563.8	3,432.7
Gross Profit	389.3	487.2	517.5	340.9	1,734.8	1,777.5	1,549.2
Operating Income (Loss)	195.8	328.8	349.0	168.0	1,041.5	1,040.4	791.5
Income before income taxes	178.7	317.4	340.0	160.8	996.8	999.4	738.9
Income Tax Expense (Benefit)	36.2	57.5	66.1	31.2	191.0	188.3	147.7
Net Income (Loss) Attributable to Parent	$ 142.5	$ 259.9	$ 273.9	$ 129.6	$ 805.8	$ 811.1	$ 591.2
Basic Earnings (Loss) per Share (in usd per share)	$ 4.08	$ 7.41	$ 7.75	$ 3.65	$ 22.89	$ 22.78	$ 16.65
Diluted Earnings (Loss) per Share (in usd per share)	$ 4.07	$ 7.38	$ 7.71	$ 3.63	$ 22.79	$ 22.66	$ 16.58
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues	$ 1,195.0	$ 1,426.8	$ 1,500.9	$ 1,072.6		$ 5,341.3	$ 4,981.9
Cost of goods sold	809.4	958.2	978.4	744.1		3,569.4	3,434.1
Gross Profit	385.6	468.6	522.5	328.5		1,771.9	1,547.8
Operating Income (Loss)	192.1	310.2	354.0	155.6		1,034.8	790.1
Income before income taxes	175.0	298.8	345.0	148.4		993.8	737.5
Income Tax Expense (Benefit)	35.3	53.0	67.4	28.1		186.9	147.4
Net Income (Loss) Attributable to Parent	$ 139.7	$ 245.8	$ 277.6	$ 120.3		$ 806.9	$ 590.1
Basic Earnings (Loss) per Share (in usd per share)	$ 4.00	$ 7.01	$ 7.86	$ 3.39		$ 22.67	$ 16.61
Diluted Earnings (Loss) per Share (in usd per share)	$ 3.99	$ 6.98	$ 7.82	$ 3.37		$ 22.54	$ 16.54
Inventory Calculated Using LIFO
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold					$ 3,481.2
Income before income taxes					976.1
Income Tax Expense (Benefit)					186.0
Net Income (Loss) Attributable to Parent					$ 790.1
Basic Earnings (Loss) per Share (in usd per share)					$ 22.45
Diluted Earnings (Loss) per Share (in usd per share)					$ 22.32
Effect of Change
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues						$ 0.0	$ 0.0
Cost of goods sold					$ (20.7)	(5.6)	(1.4)
Gross Profit						5.6	1.4
Operating Income (Loss)						5.6	1.4
Income before income taxes					20.7	5.6	1.4
Income Tax Expense (Benefit)					5.0	1.4	0.3
Net Income (Loss) Attributable to Parent					$ 15.7	$ 4.2	$ 1.1
Basic Earnings (Loss) per Share (in usd per share)					$ (0.44)	$ 0.11	$ 0.04
Diluted Earnings (Loss) per Share (in usd per share)					$ (0.47)	$ 0.12	$ 0.04