Condensed Consolidated Statements of Income (Unaudited) - USD ($)
shares in Thousands, $ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jul. 01, 2016
Jun. 30, 2017
Jul. 01, 2016
Income Statement [Abstract]        
Revenue $ 259,318 $ 307,895 $ 549,380 $ 618,577
Cost of revenue 233,583 280,644 498,283 564,354
Selling, general and administrative expenses 16,531 15,953 30,244 31,113
Operating income 9,204 11,298 20,853 23,110
Interest (expense) income, net (1,070) (1,736) (2,204) (3,048)
Income from operations before income taxes 8,134 9,562 18,649 20,062
Income tax expense 2,673 3,512 6,520 7,422
Net income $ 5,461 $ 6,050 $ 12,129 $ 12,640
Earnings Per Share        
Basic (in dollars per share) $ 0.50 $ 0.57 $ 1.11 $ 1.19
Diluted (in dollars per share) $ 0.49 $ 0.55 $ 1.09 $ 1.16
Weighted average common shares outstanding - basic (in shares) 10,987 10,702 10,948 10,665
Weighted average common shares outstanding - diluted (in shares) 11,191 10,958 11,132 10,913