Business Segments - Summary of Segment Operating Results (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	$ 178,200		$ 321,757	$ 707,699	$ 957,000
Aluminum and other material costs	92,198		151,888	359,354	460,824
Manufacturing costs	102,871		119,697	332,694	349,753
Manufacturing depreciation and amortization	12,312		21,538	50,180	65,023
Selling, general and administrative expenses	26,360		23,900	66,699	66,108
Impairment of long-lived assets		$ 66,900		66,906
Segment expenses	233,741		317,023	875,833	941,708
Income (loss) from operations	(55,541)		4,734	(168,134)	15,292
Supplemental Segment Financial Information:
Depreciation and amortization	12,445		21,700	50,610	65,534
Capital expenditures	7,022		6,141	18,933	20,985
Long-lived assets:
Property, plant, and equipment	274,039			274,039		$ 329,892
Intangible assets	4,516			4,516		12,612
Segment assets	591,969			591,969		740,129
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	73,538		206,233	371,050	602,944
Aluminum and other material costs	42,475		106,925	209,221	313,937
Manufacturing costs	55,123		63,811	177,085	190,880
Manufacturing depreciation and amortization	4,853		9,865	21,697	30,325
Selling, general and administrative expenses	20,125		11,739	47,648	32,632
Impairment of long-lived assets				66,906
Segment expenses	122,576		192,340	522,557	567,774
Income (loss) from operations	(49,038)		13,893	(151,507)	35,170
Supplemental Segment Financial Information:
Depreciation and amortization	4,960		9,968	22,009	30,645
Capital expenditures	2,708		3,041	7,615	11,611
Long-lived assets:
Property, plant, and equipment	104,336			104,336		174,180
Segment assets	276,382			276,382		407,800
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	104,662		115,524	336,649	354,056
Aluminum and other material costs	49,723		44,963	150,133	146,887
Manufacturing costs	47,748		55,886	155,609	158,873
Manufacturing depreciation and amortization	7,459		11,673	28,483	34,698
Selling, general and administrative expenses	6,235		12,161	19,051	33,476
Segment expenses	111,165		124,683	353,276	373,934
Income (loss) from operations	(6,503)		(9,159)	(16,627)	(19,878)
Supplemental Segment Financial Information:
Depreciation and amortization	7,485		11,732	28,601	34,889
Capital expenditures	4,314		$ 3,100	11,318	$ 9,374
Long-lived assets:
Property, plant, and equipment	169,703			169,703		155,712
Intangible assets	4,516			4,516		12,612
Segment assets	$ 315,587			$ 315,587		$ 332,329