Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Operating revenues	$ 2,849,685	$ 2,854,390	$ 2,699,250
Cost of sales	2,510,234	2,532,472	2,423,204
Gross profit	339,451	321,918	276,046
Selling, general and administrative expenses	149,544	131,375	111,402
Operating income	189,907	190,543	164,644
Interest expense	14,023	16,954	6,354
Other income	4,875	3,981	1,379
Income before income taxes and income from equity method investments	180,759	177,570	159,669
Income taxes expense	49,523	45,286	40,788
Income from equity method investments	12,185	4,946	5,900
Net income	$ 143,421	$ 137,230	$ 124,781
Earnings per share:
Earnings per share - basic (in dollars per share)	$ 2.81	$ 2.69	$ 2.45
Earnings per share - diluted (in dollars per share)	$ 2.81	$ 2.69	$ 2.45
Weighted average common shares outstanding:
Weighted average common shares outstanding - basic (in shares)	50,973	50,972	50,972
Weighted average common shares outstanding - diluted (in shares)	51,072	50,972	50,972