Revenue Recognition (Tables)

9 Months Ended

Sep. 27, 2019

Revenue Recognition [Abstract]

Summary of Revenues

The Company recognized the following revenues from time and materials contracts:

	Three Months Ended						Nine Months Ended
	September 27, 2019			September 28, 2018			September 27, 2019			September 28, 2018
Engineering & other scientific	$	68,859		$	59,582		$	205,999		$	186,486
Environmental and health		17,803			16,755			54,612			52,987
Total time and materials revenues		86,662			76,337			260,611			239,473
Percent of total revenues		85.3	%		80.1	%		84.9	%		83.3	%

The Company recognized the following revenues from fixed price contracts:

	Three Months Ended						Nine Months Ended
	September 27, 2019			September 28, 2018			September 27, 2019			September 28, 2018
Engineering & other scientific		14,201			18,315			44,135			45,494
Environmental and health		685			650			2,339			2,413
Total fixed price revenues		14,886			18,965			46,474			47,907
Percent of total revenues		14.7	%		19.9	%		15.1	%		16.7	%