General - Consolidated Statements of Operations (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2026	Mar. 31, 2025
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Goods Sold	[1]	$ 530.4	$ 576.6
Gross profit		118.8	57.3
Operating income		374.0	42.8
Income before income taxes		328.8	24.0
Net income		327.0	22.4
Net loss attributable to noncontrolling interests		(10.5)	(7.3)
Net income attributable to Century stockholders		337.5	29.7
Less: net income allocated to participating securities		0.0	1.5
Net income allocated to common stockholders		$ 337.5	28.2
As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Goods Sold			573.3
Gross profit			60.6
Operating income			46.1
Income before income taxes			27.3
Net income			25.7
Net loss attributable to noncontrolling interests			(4.0)
Net income attributable to Century stockholders			29.7
Less: net income allocated to participating securities			1.5
Net income allocated to common stockholders			28.2
Restatement Impacts
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Goods Sold			3.3
Gross profit			(3.3)
Operating income			(3.3)
Income before income taxes			(3.3)
Net income			(3.3)
Net loss attributable to noncontrolling interests			(3.3)
Net income attributable to Century stockholders			0.0
Less: net income allocated to participating securities			0.0
Net income allocated to common stockholders			$ 0.0

[1] (1) Purchases from related party were $64.2 million and $88.3 million for the three months ended March 31, 2026 and 2025, respectively.