Revenue (Tables)
 9 Months Ended
Oct. 01, 2021
Revenue from Contract with Customer [Abstract]  
Remaining Performance Obligation
Remaining performance obligations as of October 1, 2021 and December 31, 2020 are presented in the following table:
October 1,December 31,
(In millions)20212020
Performance Obligations$1,560 $993 
Disaggregation of Revenue
The following tables present our revenue disaggregated by several categories. Revenue by contract type for the three and nine months ended October 1, 2021 and October 2, 2020 is as follows:
Three Months EndedNine Months Ended
October 1,October 2,%October 1,October 2,%
(In thousands)20212020Change20212020Change
Cost-plus and cost-reimbursable ¹$353,789 $249,484 41.8 %$1,018,465 $748,543 36.1 %
Firm-fixed-price105,619 102,931 2.6 %345,792 291,669 18.6 %
Total revenue$459,408 $352,415 $1,364,257 $1,040,212 
¹ Includes time and material contracts
Revenue by geographic region in which the contract is performed for the three and nine months ended October 1, 2021 and October 2, 2020 is as follows:
Three Months EndedNine Months Ended
October 1,October 2,%October 1,October 2,%
(In thousands)20212020Change20212020Change
Middle East$263,257 $223,544 17.8 %$761,758 $677,449 12.4 %
United States139,357 87,979 58.4 %435,717 250,900 73.7 %
Europe34,902 38,108 (8.4)%111,604 106,171 5.1 %
Asia21,892 2,784 686.3 %55,178 5,692 869.4 %
Total revenue$459,408 $352,415 $1,364,257 $1,040,212 

Revenue by contract relationship for the three and nine months ended October 1, 2021 and October 2, 2020 is as follows:
Three Months EndedNine Months Ended
October 1,October 2,%October 1,October 2,%
(In thousands)20212020Change20212020Change
Prime contractor$429,370 $332,564 29.1 %$1,272,671 $980,301 29.8 %
Subcontractor30,038 19,851 51.3 %91,586 59,911 52.9 %
Total revenue$459,408 $352,415 $1,364,257 $1,040,212 

Revenue by customer for the three and nine months ended October 1, 2021 and October 2, 2020 is as follows:
Three Months EndedNine Months Ended
October 1,October 2,%October 1,October 2,%
(In thousands)20212020Change20212020Change
Army$304,341 $236,267 28.8 %$869,690 $711,173 22.3 %
Air Force63,569 79,425 (20.0)%207,565 231,088 (10.2)%
Navy52,556 18,785 179.8 %165,391 48,564 240.6 %
Other38,942 17,938 117.1 %121,611 49,387 146.2 %
Total revenue$459,408 $352,415 $1,364,257 $1,040,212