Revenue
 9 Months Ended
Oct. 02, 2020
Revenue from Contract with Customer [Abstract]  
Revenue
REVENUE
Performance Obligations
    A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account for revenue in ASC Topic 606. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. To determine the proper revenue recognition method, consideration is given as to whether a single contract should be accounted for as more than one performance obligation. For most of our contracts, the customer contracts with us to perform an integrated set of tasks and deliverables as a single service solution, whereby each service is not separately identifiable from other promises in the contract and therefore is not distinct. As a result, when this integrated set of tasks exists, the contract is accounted for as one performance obligation. The vast majority of our contracts have a single performance obligation. Unexercised contract options and indefinite delivery and indefinite quantity (IDIQ) contracts are considered to be separate performance obligations when the option or IDIQ task order is exercised or awarded.
    Contract modifications are routine in the performance of our contracts. Contracts are often modified to account for changes in contract specifications or requirements. In most instances, contract modifications are for goods or services that are not distinct, and therefore, are accounted for as part of the existing contract. Modifications to exercise option years create new enforceable rights and obligations and therefore are treated as separate performance obligations.
    The Company's performance obligations are typically satisfied over time as services are provided throughout the contract term. We recognize revenue over time using the input method (e.g., costs incurred to date relative to total estimated costs at completion) to measure progress. Our over time recognition is reinforced by the fact that our customers simultaneously receive and consume the benefits of our services as they are performed. This continuous transfer of control requires that we track progress towards completion of performance obligations in order to measure and recognize revenue. Determining progress on performance obligations requires us to make judgments that affect the timing of revenue recognition. Remaining performance obligations represent firm orders by the customer and excludes potential orders under IDIQ contracts, unexercised contract options, and contracts awarded to us that are being protested by competitors with the U.S. Government Accountability Office (GAO) or in the U.S. Court of Federal Claims. The level of order activity related to contracts can be affected by the timing of government funding authorizations and their project evaluation cycles. Year-over-year comparisons could, at times, be impacted by these factors, among others.
    The Company's contracts are multi-year contracts and typically include an initial period of one year or less with annual one-year (or less) option periods. The number of option periods varies by contract, and there is no guarantee that an option period will be exercised. The right to exercise an option period is at the sole discretion of the U.S. Government when we are the prime contractor or of the prime contractor when we are a subcontractor. We expect to recognize a substantial portion of our performance obligations as revenue within the next 12 months. However, the U.S. Government or the prime contractor may cancel any contract at any time through a termination for convenience or for cause. Substantially all of our contracts have terms that would permit us to recover all or a portion of our incurred costs and fees for work performed in the event of a termination for convenience.
    Remaining performance obligations increased by $306.4 million as of October 2, 2020 as compared to December 31, 2019. We expect to recognize approximately 30% of the remaining performance obligations as of October 2, 2020 as revenue in 2020, and the remaining 70% during 2021. Remaining performance obligations as of October 2, 2020 and December 31, 2019 are presented in the following table:
October 2,December 31,
(In thousands)20202019
Performance Obligations$1,155,742 $849,389 
Contract Estimates
    Accounting for contracts involves the use of various techniques to estimate total contract revenue and costs. We estimate the profit on our contracts as the difference between the total estimated revenue and expected costs to complete a contract and recognize that profit over the life of the contract.
    Contract estimates are based on various assumptions to project the outcome of future events. These assumptions include labor productivity and availability; the complexity of the services being performed; the cost and availability of materials; the performance of subcontractors; and the availability and timing of funding from the customer.
    The impact of adjustments in contract estimates on our operating income can be reflected in either revenue or cost of revenue. Cumulative catch-up adjustments for the three and nine months ended October 2, 2020 were favorable to operating income by less than $0.1 million and unfavorable to operating income by $3.8 million, respectively. For the three and nine months ended September 27, 2019, the net favorable adjustments to operating income were $0.7 million and $1.5 million, respectively.
    For the three and nine months ended October 2, 2020 the cumulative catch-up adjustments to operating income decreased revenue by $1.1 million and $0.5 million, respectively. For the three and nine months ended September 27, 2019, the cumulative catch-up adjustments to operating income increased revenue by $4.0 million and $4.2 million, respectively.
Revenue by Category
    Generally, the sales price elements for our contracts are cost-plus, cost-reimbursable or firm-fixed-price. We commonly have elements of cost-plus, cost-reimbursable and firm-fixed-price contracts on a single contract. On a cost-plus type contract, we are paid our allowable incurred costs plus a profit, which can be fixed or variable depending on the contract’s fee arrangement, up to funding levels predetermined by our customers. On cost-plus type contracts, we do not bear the risks of unexpected cost overruns, provided that we do not incur costs that exceed the predetermined funded amounts. Cost-plus type contracts with award and incentive fee provisions are our primary variable contract fee arrangement. Award fees provide for a fee based on actual performance relative to contractually specified performance criteria. Incentive fees provide for a fee based on the relationship between total allowable and target cost. On most of our contracts, a cost-reimbursable element captures consumable materials required for the contract. Typically, these costs do not bear fees.
    On a firm-fixed-price type contract, we agree to perform the contractual statement of work for a predetermined contract price. A firm-fixed-price type contract typically offers higher profit margin potential than a cost-plus type contract, which is commensurate with the greater levels of risk we assume on a firm-fixed-price type contract. Although a firm-fixed-price type contract generally permits us to retain profits if the total actual contract costs are less than the estimated contract costs, we bear the risk that increased or unexpected costs may reduce our profit or cause us to sustain losses on the contract. Although the overall scope of work required under the contract may not change, profit may be adjusted as experience is gained and as efficiencies are realized or costs are incurred.
    The following tables present our revenue disaggregated by several categories. Revenue by contract type for the three and nine months ended October 2, 2020 and September 27, 2019 is as follows:
Three Months EndedNine Months Ended
October 2,September 27,%October 2,September 27,%
(In thousands)20202019Change20202019Change
Cost-plus and cost-reimbursable ¹$249,484 $272,810 (8.6)%$748,543 $781,024 (4.2)%
Firm-fixed-price102,931 87,063 18.2 %291,669 236,344 23.4 %
Total revenue$352,415 $359,873 $1,040,212 $1,017,368 
¹ Includes time and material contracts
    Revenue by geographic region in which the contract is performed for the three and nine months ended October 2, 2020 and September 27, 2019 is as follows:
Three Months EndedNine Months Ended
October 2,September 27,%October 2,September 27,%
(In thousands)20202019Change20202019Change
Middle East$224,934 $244,142 (7.9)%$679,633 $695,626 (2.3)%
United States89,400 77,228 15.8 %254,640 219,512 16.0 %
Europe38,081 38,503 (1.1)%105,939 102,230 3.6 %
Total revenue$352,415 $359,873 $1,040,212 $1,017,368 

    Revenue by contract relationship for the three and nine months ended October 2, 2020 and September 27, 2019 is as follows:
Three Months EndedNine Months Ended
October 2,September 27,%October 2,September 27,%
(In thousands)20202019Change20202019Change
Prime contractor$332,564 $334,402 (0.5)%$980,301 $954,191 2.7 %
Subcontractor19,851 25,471 (22.1)%59,911 63,177 (5.2)%
Total revenue$352,415 $359,873 $1,040,212 $1,017,368 

    Revenue by customer for the three and nine months ended October 2, 2020 and September 27, 2019 is as follows:
Three Months EndedNine Months Ended
October 2.September 27,%October 2.September 27,%
(In thousands)20202019Change20202019Change
Army$236,267 $245,817 (3.9)%$711,173 $698,377 1.8 %
Air Force79,425 86,576 (8.3)%231,088 227,100 1.8 %
Navy18,785 13,344 40.8 %48,564 45,227 7.4 %
Other17,938 14,136 26.9 %49,387 46,664 5.8 %
Total revenue$352,415 $359,873 $1,040,212 $1,017,368 
Contract Balances
    The timing of revenue recognition, billings and cash collections results in billed and unbilled accounts receivable (contract assets) and customer advances and deposits (contract liabilities) on the Condensed Consolidated Balance Sheets. Amounts are billed as work progresses in accordance with agreed-upon contractual terms at periodic intervals (e.g., biweekly or monthly). Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. However, we may receive advances or deposits from our customers, before revenue is recognized, resulting in contract liabilities. These advance billings and payments are not considered significant financing components because they are frequently intended to ensure that both parties are in conformance with the primary contract terms. These assets and liabilities are reported on the Condensed Consolidated Balance Sheets on a contract-by-contract basis at the end of each reporting period.
    As of October 2, 2020 and December 31, 2019, we had contract assets of $199.3 million and $186.4 million, respectively. Refer to Note 8, "Receivables" for additional information regarding the composition of our receivable balances. As of both October 2, 2020 and December 31, 2019, our contract liabilities were insignificant.