Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net sales	$ 388,812	$ 387,553	$ 377,692	$ 216,259	$ 304,632	$ 394,991	$ 396,255	$ 259,708	$ 593,951	$ 655,963	$ 981,504	$ 1,050,954	$ 1,370,316	$ 1,355,586	$ 1,178,974
Cost of sales		255,639	266,818	174,072		271,755	280,694	176,274	440,890	456,968	696,529	728,723	940,048	956,921	794,667
Gross profit	145,293	131,914	110,874	42,187	76,434	123,236	115,561	83,434	153,061	198,995	284,975	322,231	430,268	398,665	384,307
Selling, general and administrative expenses		72,490	74,211	73,510		78,845	70,415	63,151	147,721	133,566	220,211	212,411	305,162	279,889	244,205
Other general expenses		1,065									1,065		1,065		2,592
Loss on disposal of plant, property and equipment		95	249	(66)		(108)	407	18	183	425	278	317	249	496	1,025
Operating income (loss)		58,264	36,414	(31,257)		44,499	44,739	20,265	5,157	65,004	63,421	109,503	123,792	118,280	136,485
Other expenses:
Interest expense, net		10,408	10,774	9,299		10,618	4,010	4,148	20,073	8,158	30,481	18,776	39,293	24,956	20,311
Total other expenses		10,408	10,774	9,299		10,618	4,010	4,148	20,073	8,158	30,481	18,776	39,293	24,956	20,311
Income (loss) before income taxes		47,856	25,640	(40,556)		33,881	40,729	16,117	(14,916)	56,846	32,940	90,727	84,499	93,324	116,174
Income tax expense		13,216	7,415	(10,821)		8,745	10,109	3,317	(3,406)	13,426	9,810	22,171	22,138	26,166	27,309
Net income (loss)	$ 39,231	34,640	18,225	(29,735)	$ (1,398)	25,136	30,620	12,800	(11,510)	43,420	23,130	68,556	62,361	67,158	88,865
Other comprehensive income:
Unrealized gain due to change in fair value of derivatives, net of tax		3,953	(1,466)	(1,796)					(3,262)		691		1,878
Total other comprehensive income (loss)		3,953	(1,466)	(1,796)					(3,262)		691		1,878
Comprehensive income		$ 38,593	$ 16,759	$ (31,531)		$ 25,136	$ 30,620	$ 12,800	$ (14,772)	$ 43,420	$ 23,821	$ 68,556	$ 64,239	$ 67,158	$ 88,865
Net income (loss) per common share:
Basic	$ 0.26	$ 0.23	$ 0.12	$ (0.2)	$ (0.01)	$ 0.16	$ 0.2	$ 0.08	$ (0.08)	$ 0.28	$ 0.15	$ 0.44	$ 0.42	$ 0.44	$ 0.58
Diluted	$ 0.26	$ 0.23	$ 0.12	$ (0.2)	$ (0.01)	$ 0.16	$ 0.2	$ 0.08	$ (0.08)	$ 0.28	$ 0.15	$ 0.44	$ 0.41	$ 0.43	$ 0.57
Weighted average shares used in calculating net income (loss) per common share:
Basic		150,140,392	150,713,075	150,877,635		153,493,355	154,661,277	154,407,244	150,812,859	154,551,589	150,610,890	154,199,158	150,162,256	153,510,110	153,777,859
Diluted		151,069,954	151,268,535	150,877,635		153,891,090	156,121,476	156,854,925	150,812,859	156,560,502	151,056,199	155,631,884	150,849,896	154,517,843	156,666,394