Changes in Estimates	3 Months Ended
Sep. 30, 2016
Change in Accounting Estimate [Abstract]
Changes in Estimates	Changes in Estimates Estimates and assumptions, and changes therein, are important in connection with, among others, our segments’ revenue recognition policies related to development and production contracts. Revenue and profits related to development and production contracts are recognized using the percentage-of-completion method, generally based on the ratio of costs incurred to estimated total costs at completion (i.e., the “cost-to-cost” method) or the ratio of actual units delivered to estimated total units to be delivered under the contract (i.e., the “units-of-delivery” method) with consideration given for risk of performance and estimated profit. Revenue and profits on cost-reimbursable development and production contracts are recognized as allowable costs are incurred on the contract, and become billable to the customer, in an amount equal to the allowable costs plus the profit on those costs. Development and production contracts are combined when specific aggregation criteria are met. Criteria generally include closely interrelated activities performed for a single customer within the same economic environment. Development and production contracts are generally not segmented. If development and production contracts are segmented, we have determined that they meet specific segmenting criteria. Change orders, claims or other items that may change the scope of a development and production contract are included in contract value only when the value can be reliably estimated and realization is probable. Possible incentives or penalties and award fees applicable to performance on development and production contracts are considered in estimating contract value and profit rates and are recorded when there is sufficient information to assess anticipated contract performance. Incentive provisions that increase earnings based solely on a single significant event are generally not recognized until the event occurs. We are party to certain contracts with incentive provisions or award fees that are subject to uncertainty until the conclusion of the contract and our customer may be entitled to reclaim and receive previous award fee payments. Under the percentage-of-completion method of accounting, a single estimated total profit margin is used to recognize profit for each development and production contract over its period of performance. Recognition of profit on development and production fixed-price contracts requires estimates of the total cost at completion and the measurement of progress toward completion. The estimated profit or loss on a development and production contract is equal to the difference between the estimated contract value and the estimated total cost at completion. Due to the long-term nature of many of our programs, developing the estimated total cost at completion often requires judgment. Factors that must be considered in estimating the cost of the work to be completed include the nature and complexity of the work to be performed, subcontractor performance, the risk and impact of delayed performance, availability and timing of funding from the customer and the recoverability of any claims outside the original development and production contract included in the estimate to complete. At the outset of each contract, we gauge its complexity and perceived risks and establish an estimated total cost at completion in line with these expectations. After establishing the estimated total cost at completion, we follow a standard estimate at completion (“EAC”) process in which management reviews the progress and performance on our ongoing development and production contracts at least quarterly and, in many cases, more frequently. If we successfully retire risks associated with the technical, schedule and cost aspects of a contract, we may lower our estimated total cost at completion commensurate with the retirement of these risks. Conversely, if we are not successful in retiring these risks, we may increase our estimated total cost at completion. Additionally, at the outset of a cost-reimbursable contract (for example, contracts containing award or incentive fees), we establish an estimated total contract value, or revenue, based on our expectation of performance on the contract. As the cost-reimbursable contract progresses, our estimates of total contract value may increase or decrease if, for example, we receive higher or lower than expected award fees. When adjustments in estimated total costs at completion or in estimated total contract value are determined, the related impact to operating income is recognized using the cumulative catch-up method, which recognizes in the current period the cumulative effect of such adjustments for all prior periods. Anticipated losses on development and production contracts or programs in progress are charged to operating income when identified. Net EAC adjustments resulting from changes in estimates favorably impacted our operating income by $13 million ($0.07 per diluted share) in the quarter ended September 30, 2016 and by $17 million ($0.08 per diluted share) in the quarter ended October 2, 2015.

Changes in Estimates

Estimates and assumptions, and changes therein, are important in connection with, among others, our segments’ revenue recognition policies related to development and production contracts. Revenue and profits related to development and production contracts are recognized using the percentage-of-completion method, generally based on the ratio of costs incurred to estimated total costs at completion (i.e., the “cost-to-cost” method) or the ratio of actual units delivered to estimated total units to be delivered under the contract (i.e., the “units-of-delivery” method) with consideration given for risk of performance and estimated profit. Revenue and profits on cost-reimbursable development and production contracts are recognized as allowable costs are incurred on the contract, and become billable to the customer, in an amount equal to the allowable costs plus the profit on those costs.

Development and production contracts are combined when specific aggregation criteria are met. Criteria generally include closely interrelated activities performed for a single customer within the same economic environment. Development and production contracts are generally not segmented. If development and production contracts are segmented, we have determined that they meet specific segmenting criteria. Change orders, claims or other items that may change the scope of a development and production contract are included in contract value only when the value can be reliably estimated and realization is probable. Possible incentives or penalties and award fees applicable to performance on development and production contracts are considered in estimating contract value and profit rates and are recorded when there is sufficient information to assess anticipated contract performance. Incentive provisions that increase earnings based solely on a single significant event are generally not recognized until the event occurs. We are party to certain contracts with incentive provisions or award fees that are subject to uncertainty until the conclusion of the contract and our customer may be entitled to reclaim and receive previous award fee payments.

Under the percentage-of-completion method of accounting, a single estimated total profit margin is used to recognize profit for each development and production contract over its period of performance. Recognition of profit on development and production fixed-price contracts requires estimates of the total cost at completion and the measurement of progress toward completion. The estimated profit or loss on a development and production contract is equal to the difference between the estimated contract value and the estimated total cost at completion. Due to the long-term nature of many of our programs, developing the estimated total cost at completion often requires judgment. Factors that must be considered in estimating the cost of the work to be completed include the nature and complexity of the work to be performed, subcontractor performance, the risk and impact of delayed performance, availability and timing of funding from the customer and the recoverability of any claims outside the original development and production contract included in the estimate to complete. At the outset of each contract, we gauge its complexity and perceived risks and establish an estimated total cost at completion in line with these expectations. After establishing the estimated total cost at completion, we follow a standard estimate at completion (“EAC”) process in which management reviews the progress and performance on our ongoing development and production contracts at least quarterly and, in many cases, more frequently. If we successfully retire risks associated with the technical, schedule and cost aspects of a contract, we may lower our estimated total cost at completion commensurate with the retirement of these risks. Conversely, if we are not successful in retiring these risks, we may increase our estimated total cost at completion. Additionally, at the outset of a cost-reimbursable contract (for example, contracts containing award or incentive fees), we establish an estimated total contract value, or revenue, based on our expectation of performance on the contract. As the cost-reimbursable contract progresses, our estimates of total contract value may increase or decrease if, for example, we receive higher or lower than expected award fees. When adjustments in estimated total costs at completion or in estimated total contract value are determined, the related impact to operating income is recognized using the cumulative catch-up method, which recognizes in the current period the cumulative effect of such adjustments for all prior periods. Anticipated losses on development and production contracts or programs in progress are charged to operating income when identified. Net EAC adjustments resulting from changes in estimates favorably impacted our operating income by $13 million ($0.07 per diluted share) in the quarter ended September 30, 2016 and by $17 million ($0.08 per diluted share) in the quarter ended October 2, 2015.