Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Income Statement [Abstract]
Sales	$ 314,842	$ 204,594
Cost of goods sold	266,038	167,099
Gross profit	48,804	37,495
Operating expenses:
Research and development	3,029	2,906
Sales and marketing	3,805	3,051
General and administrative	15,062	11,765
Total operating expenses	21,896	17,722
Income from operations	26,908	19,773
Interest and other income (expense), net	326	(938)
Income before provision for income taxes	27,234	18,835
Income tax provision	2,493	4,494
Net income	$ 24,741	$ 14,341
Net income per share:
Basic	$ 0.67	$ 0.43
Diluted	$ 0.66	$ 0.42
Shares used in computing net income per share:
Basic	36,723	33,061
Diluted	37,491	33,865