Condensed Consolidated Statements of Stockholders Equity (Unaudited) - USD ($) $ in Thousands	Total	Previously Reported	Restatement Adjustment	Total PAE Incorporated Stockholders' Equity	Total PAE Incorporated Stockholders' Equity Previously Reported	Common Stock	Common Stock Previously Reported	Common Stock Restatement Adjustment	Additional Paid-in Capital	Additional Paid-in Capital Previously Reported	Additional Paid-in Capital Restatement Adjustment	Accumulated Deficit	Accumulated Deficit Previously Reported	Accumulated Other Comprehensive (Loss) / Income	Accumulated Other Comprehensive (Loss) / Income Previously Reported	Noncontrolling Interests	Noncontrolling Interests Previously Reported
Beginning balance at Dec. 31, 2018	$ 31,485	$ 31,485	$ 0	$ 4,045	$ 4,045	$ 2	$ 3	$ (1)	$ 101,743	$ 101,742	$ 1	$ (95,562)	$ (95,562)	$ (2,138)	$ (2,138)	$ 27,440	$ 27,440
Beginning balance (in shares) at Dec. 31, 2018						21,127,823	282,047	20,845,776
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(5,160)			(5,719)								(5,719)				559
Other comprehensive income (loss), net	712			712										712
Equity contributions from venture partners	1,350															1,350
Ending balance at Mar. 31, 2019	28,387			(962)		$ 2			101,743			(101,281)		(1,426)		29,349
Ending balance (in shares) at Mar. 31, 2019						21,127,823
Beginning balance at Dec. 31, 2018	31,485	31,485	0	4,045	4,045	$ 2	$ 3	$ (1)	101,743	101,742	1	(95,562)	(95,562)	(2,138)	(2,138)	27,440	27,440
Beginning balance (in shares) at Dec. 31, 2018						21,127,823	282,047	20,845,776
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(33,397)
Other comprehensive income (loss), net	708
Ending balance at Sep. 29, 2019	3,455			(30,462)		$ 2			101,743			(130,777)		(1,430)		33,917
Ending balance (in shares) at Sep. 29, 2019						21,127,823
Beginning balance at Mar. 31, 2019	28,387			(962)		$ 2			101,743			(101,281)		(1,426)		29,349
Beginning balance (in shares) at Mar. 31, 2019						21,127,823
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	3,389			2,674								2,674				715
Other comprehensive income (loss), net	6			6										6
Net contributions from noncontrolling interests	4,050															4,050
Distributions to venture partners and other	(742)															(742)
Ending balance at Jun. 30, 2019	35,090			1,718		$ 2			101,743			(98,607)		(1,420)		33,372
Ending balance (in shares) at Jun. 30, 2019						21,127,823
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(31,625)			(32,170)								(32,170)				545
Other comprehensive income (loss), net	(10)			(10)										(10)
Ending balance at Sep. 29, 2019	3,455			(30,462)		$ 2			101,743			(130,777)		(1,430)		33,917
Ending balance (in shares) at Sep. 29, 2019						21,127,823
Beginning balance at Dec. 31, 2019	$ (11,909)	(11,909)	0	(43,760)	(43,760)	$ 2	$ 3	$ (1)	101,743	101,742	1	(145,371)	(145,371)	(134)	(134)	31,851	31,851
Beginning balance (in shares) at Dec. 31, 2019	21,127,823					21,127,823	282,047	20,845,776
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	$ (4,777)			(4,943)								(4,943)				166
Other comprehensive income (loss), net	(695)			(695)										(695)
Distributions to venture partners and other	152															152
Equity contributions from venture partners	13			13					13
Equity infusion from Gores III	364,778			364,778		$ 5			364,773
Equity infusion from Gores III (in shares)						46,999,787
Private placement	220,000			220,000		$ 2			219,998
Private placement (in shares)						23,913,044
Payment to Shay Stockholders	(424,243)			(424,243)					(424,243)
Ending balance at Mar. 29, 2020	143,319			111,150		$ 9			262,284			(150,314)		(829)		32,169
Ending balance (in shares) at Mar. 29, 2020						92,040,654
Beginning balance at Dec. 31, 2019	$ (11,909)	$ (11,909)	$ 0	(43,760)	$ (43,760)	$ 2	$ 3	$ (1)	101,743	$ 101,742	$ 1	(145,371)	$ (145,371)	(134)	$ (134)	31,851	$ 31,851
Beginning balance (in shares) at Dec. 31, 2019	21,127,823					21,127,823	282,047	20,845,776
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	$ 22,739
Other comprehensive income (loss), net	287
Ending balance at Sep. 27, 2020	$ 162,009			126,992		$ 9			250,805			(123,975)		153		35,017
Ending balance (in shares) at Sep. 27, 2020	92,040,654					92,040,654
Beginning balance at Mar. 29, 2020	$ 143,319			111,150		$ 9			262,284			(150,314)		(829)		32,169
Beginning balance (in shares) at Mar. 29, 2020						92,040,654
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	16,786			16,021								16,021				765
Other comprehensive income (loss), net	201			201										201
Distributions to venture partners and other	(443)															(443)
Equity contributions from venture partners	1,939															1,939
Payment to Shay Stockholders	(20,169)			(20,169)					(20,169)
Stock-based compensation	3,700			3,700					3,700
Ending balance at Jun. 28, 2020	145,333			110,903		$ 9			245,815			(134,293)		(628)		34,430
Ending balance (in shares) at Jun. 28, 2020						92,040,654
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	10,731			10,318								10,318				413
Other comprehensive income (loss), net	781			781										781
Equity contributions from venture partners	28			(146)					(146)							174
Payment to Shay Stockholders	818			818					818
Stock-based compensation	4,318			4,318					4,318
Ending balance at Sep. 27, 2020	$ 162,009			$ 126,992		$ 9			$ 250,805			$ (123,975)		$ 153		$ 35,017
Ending balance (in shares) at Sep. 27, 2020	92,040,654					92,040,654