Condensed Consolidated Statements of Income (Unaudited) - USD ($)
shares in Thousands, $ in Thousands
3 Months Ended
Mar. 30, 2018
Mar. 31, 2017
Income Statement [Abstract]    
Revenue $ 320,516 $ 290,063
Cost of revenue 294,050 264,701
Selling, general and administrative expenses 17,795 13,713
Operating income 8,671 11,649
Interest (expense) income, net (1,164) (1,134)
Income from operations before income taxes 7,507 10,515
Income tax expense 1,396 3,847
Net income $ 6,111 $ 6,668
Earnings Per Share    
Basic (in dollars per share) $ 0.55 $ 0.61
Diluted (in dollars per share) $ 0.54 $ 0.60
Weighted average common shares outstanding - basic (in shares) 11,146 10,909
Weighted average common shares outstanding - diluted (in shares) 11,338 11,075