Summary of Significant Accounting Policies	3 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Revenue Recognition and Contract Balances The Company's revenue is principally from contracts with customers to provide design, development, manufacturing, and support services associated with specific customer programs. The Company regularly enters into long-term master supply agreements that establish general terms and conditions and may define specific program requirements. Many agreements include clauses that provide sole supplier status to the Company for the duration of the program’s life. Purchase orders (or authorizations to proceed) are issued pursuant to the master supply agreements. Additionally, a majority of the Company’s agreements with customers include options for future purchases. Such options primarily reduce the administrative effort of issuing subsequent purchase orders and do not represent material rights granted to customers. The Company generally enters into agreements directly with its customers and is the principal in all current contracts. The identification of a contract with a customer for purposes of accounting and financial reporting requires an evaluation of the terms and conditions of agreements to determine whether presently enforceable rights and obligations exist. Management considers a number of factors when making this evaluation that include, but are not limited to, the nature and substance of the business exchange, the specific contractual terms and conditions, the promised products and services, the termination provisions in the contract, as well as the nature and execution of the customer’s ordering process and how the Company is authorized to perform work. Generally, presently enforceable rights and obligations are not created until a purchase order is issued by a customer for a specified number of units of product or services. Therefore, the issuance of a purchase order is generally the point at which a contract is identified for accounting and financial reporting purposes. Management identifies the promises to the customer. Promises are generally explicitly stated in each contract, but management also evaluates whether any promises are implied based on the terms of the agreement, past business practice, or other facts and circumstances. Each promise is evaluated to determine if it is a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service. The Company considers a number of factors when determining whether a promise is a distinct performance obligation, including whether the customer can benefit from the good or service on its own or together with other resources that are readily available to the customer, whether the Company provides a significant service of integrating goods or services to deliver a combined output to the customer, or whether the goods or services are highly interdependent. The Company’s performance obligations consist of a wide range of engineering design services and manufactured components, as well as spare parts and repairs for OEMs. The transaction price for a contract reflects the consideration the Company expects to receive for fully satisfying the performance obligations in the contract. Typically, the transaction price consists solely of fixed consideration but may include variable consideration for contractual provisions such as unpriced contract modifications, cost-sharing provisions, and other receipts or payments to customers. The Company identifies and estimates variable consideration, typically at the most likely amount the Company expects to receive from its customers. Variable consideration is only included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized for the contract will not occur, or when the uncertainty associated with the variable consideration is resolved. The Company's contracts with customers generally require payment under normal commercial terms after delivery with payment typically required within 30 to 120 days of delivery. However, a subset of the Company’s current contracts includes significant financing components because the timing of the transfer of the underlying products and services under contract are at the customers’ discretion. For these contracts, the Company adjusts the transaction price to reflect the effects of the time value of money. The Company generally is not subject to collecting sales tax and has made an accounting policy election to exclude from the transaction price any sales and other similar taxes collected from customers. As a result, any such collections are accounted for on a net basis. The total transaction price is allocated to each of the identified performance obligations using the relative stand-alone selling price. The objective of the allocation is to reflect the consideration that the Company expects to receive in exchange for the products or services associated with each performance obligation. Stand-alone selling price is the price at which the Company would sell a promised good or service separately to a customer. Stand-alone selling prices are established at contract inception, and subsequent changes in transaction price are allocated on the same basis as at contract inception. When stand-alone selling prices for the Company’s products and services are not observable, the Company uses either the “Expected Cost Plus a Margin” or "Adjusted Market Assessment" approaches to estimate stand-alone selling price. Expected costs are typically derived from the available periodic forecast information. Revenue is recognized when or as control of promised products or services transfers to a customer and is recognized at the amount allocated to each performance obligation associated with the transferred products or services. Service sales, principally representing repair, maintenance, and engineering activities are recognized over the contractual period or as services are rendered. Sales under long-term contracts with performance obligations satisfied over time are recognized using either an input or output method. The Company recognizes revenue over time as it performs on these contracts because of the continuous transfer of control to the customer as represented by contractual terms that entitle the Company to the reimbursement of costs plus a reasonable profit for work performed to manufacture products for which the Company has no alternate use or for work performed on a customer-owned asset. With control transferring over time, revenue is recognized based on the extent of progress toward completion of the performance obligation. The Company generally uses the cost-to-cost input method of progress for its contracts because it best depicts the transfer of control to the customer that occurs as work progresses. Under the cost-to-cost method, the extent of progress toward completion is measured based on the proportion of costs incurred to date to the total estimated costs at completion of the performance obligation. The Company reviews its cost estimates on contracts on a periodic basis, or when circumstances change and warrant a modification to a previous estimate. Cost estimates are largely based on negotiated or estimated purchase contract terms, historical performance trends and other economic projections. Significant factors that influence these estimates include inflationary trends, technical and schedule risk, internal and subcontractor performance trends, business volume assumptions, asset utilization, and anticipated labor agreements. Revenue and cost estimates are regularly monitored and revised based on changes in circumstances. Impacts from changes in estimates of net sales and cost of sales are recognized on a cumulative catch-up basis, which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a performance obligation’s percentage of completion. Forward loss reserves for anticipated losses on long-term contracts are recorded in full when such losses become evident, to the extent required, and are included in contract liabilities on the accompanying condensed consolidated balance sheets. The Company believes that the accounting estimates and assumptions made by management are appropriate given the increased uncertainties surrounding the severity and duration of the impacts of the COVID-19 pandemic; however, actual results could differ materially from those estimates. For the three months ended June 30, 2021, cumulative catch-up adjustments resulting from changes in contract values and estimated costs that arose during the fiscal year increased net sales by approximately $8,737 and decreased operating loss, net loss, and loss per share by approximately $14,937, $14,937, and $0.23, respectively. For the three months ended June 30, 2020, cumulative catch-up adjustments resulting from changes in estimates increased revenue by approximately $1,560 and decreased operating loss, net loss, and loss per share by approximately $3,326, $3,326, and $0.06, respectively. Revenues for performance obligations that are not recognized over time are recognized at the point in time when control transfers to the customer. For performance obligations that are satisfied at a point in time, the Company evaluates the point in time when the customer can direct the use of and obtain the benefits from the products and services. Generally, the shipping terms determine the point in time when control transfers to customers. Shipping and handling activities are not considered performance obligations and related costs are included in cost of sales as incurred. Differences in the timing of revenue recognition and contractual billing and payment terms result in the recognition contract assets and liabilities. Refer to Note 4 for further discussion. In connection with several prior acquisitions, the Company assumed existing long-term contracts. Based on review of these contracts at the acquisition date, the Company concluded that the terms of certain contracts were either more or less favorable than could be realized in market transactions as of the date of the acquisition. As a result, the Company recognized acquired contract liabilities, net of acquired contract assets as of the acquisition date of each respective acquisition, based on the present value of the difference between the contractual cash flows of the executory contracts and the estimated cash flows had the contracts been executed at the acquisition date. The liabilities principally relate to long-term contracts that were initially executed several years prior to the respective acquisition. The Company measured these net liabilities in the year they were acquired under the measurement provisions of Accounting Standards Codification (“ASC”) 820, Fair Value Measurement, which is based on the price to transfer the obligation to a market participant at the measurement date, assuming that the net liabilities will remain outstanding in the marketplace. The portion of the Company's revenue resulting from transactions other than contracts with customers pertains to the amortization of these acquired contract liabilities as the related contractual performance obligations are satisfied. Adjustments to these liabilities due to significant changes in the total estimated costs of the contract are accounted for in a manner consistent with other loss contract reserves, with such adjustments recognized in cost of sales. Concentration of Credit Risk The Company’s trade and other accounts receivable are exposed to credit risk. However, the risk is limited due to the diversity of the customer base and the customer base’s wide geographical area. Trade accounts receivable from The Boeing Company ("Boeing") (representing commercial, military and space) represented approximately 17% and 23% of total trade accounts receivable as of June 30, 2021 and March 31, 2021, respectively. Trade and other accounts receivable from Qarbon Aerospace Inc. include receivables that are largely offset by payables associated with transition services and represented approximately 14% and 0% of total trade accounts receivable as of June 30, 2021 and March 31, 2021, respectively. The Company had no other concentrations of credit risk of more than 10%. Sales to Boeing for the three months ended June 30, 2021, were $142,102, or 36% of net sales, of which $40,053 and $102,049 were from Systems & Support and Aerospace Structures, respectively. Sales to Boeing for the three months ended June 30, 2020, were $188,137, or 38% of net sales, of which $52,022 and $136,114 were from Systems & Support and Aerospace Structures, respectively. Sales to Gulfstream Aerospace Corporation (“Gulfstream”) for the three months ended June 30, 2021, did not represent a significant concentration of credit risk. Sales to Gulfstream for the three months ended June 30, 2020, were $53,710, or 11% of net sales, of which $843 and $52,867 were from Systems & Support and Aerospace Structures, respectively. The percentage decrease in sales to Gulfstream as compared with the prior period is primarily the result of the transfer of the Company's Gulfstream G650 wing supply chain activities in August 2020. Refer to Note 3. No other single customer accounted for more than 10% of the Company’s net sales. However, the loss of any significant customer, including Boeing and Gulfstream, could have a material adverse effect on the Company and its operating subsidiaries. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. When determining fair value measurements for assets and liabilities required to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and also considers assumptions that market participants would use when pricing an asset or liability. The fair value hierarchy has three levels of inputs that may be used to measure fair value: Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities; Level 2—Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability; and Level 3—Unobservable inputs for the asset or liability. The Company has applied fair value measurements when measuring the impairment of assets held for sale (see Note 3) and to its pension and postretirement plan assets (see Note 9). Supplemental Cash Flow Information For the three months ended June 30, 2021, the Company paid $485 for income taxes, net of income tax refunds received. For the three months ended June 30, 2020, the Company paid $360 for income taxes, net of income tax refunds received.

Revenue Recognition and Contract Balances

The Company's revenue is principally from contracts with customers to provide design, development, manufacturing, and support services associated with specific customer programs. The Company regularly enters into long-term master supply agreements that establish general terms and conditions and may define specific program requirements. Many agreements include clauses that provide sole supplier status to the Company for the duration of the program’s life. Purchase orders (or authorizations to proceed)

are issued pursuant to the master supply agreements. Additionally, a majority of the Company’s agreements with customers include options for future purchases. Such options primarily reduce the administrative effort of issuing subsequent purchase orders and do not represent material rights granted to customers. The Company generally enters into agreements directly with its customers and is the principal in all current contracts.

The identification of a contract with a customer for purposes of accounting and financial reporting requires an evaluation of the terms and conditions of agreements to determine whether presently enforceable rights and obligations exist. Management considers a number of factors when making this evaluation that include, but are not limited to, the nature and substance of the business exchange, the specific contractual terms and conditions, the promised products and services, the termination provisions in the contract, as well as the nature and execution of the customer’s ordering process and how the Company is authorized to perform work. Generally, presently enforceable rights and obligations are not created until a purchase order is issued by a customer for a specified number of units of product or services. Therefore, the issuance of a purchase order is generally the point at which a contract is identified for accounting and financial reporting purposes.

Management identifies the promises to the customer. Promises are generally explicitly stated in each contract, but management also evaluates whether any promises are implied based on the terms of the agreement, past business practice, or other facts and circumstances. Each promise is evaluated to determine if it is a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service. The Company considers a number of factors when determining whether a promise is a distinct performance obligation, including whether the customer can benefit from the good or service on its own or together with other resources that are readily available to the customer, whether the Company provides a significant service of integrating goods or services to deliver a combined output to the customer, or whether the goods or services are highly interdependent. The Company’s performance obligations consist of a wide range of engineering design services and manufactured components, as well as spare parts and repairs for OEMs.

The transaction price for a contract reflects the consideration the Company expects to receive for fully satisfying the performance obligations in the contract. Typically, the transaction price consists solely of fixed consideration but may include variable consideration for contractual provisions such as unpriced contract modifications, cost-sharing provisions, and other receipts or payments to customers. The Company identifies and estimates variable consideration, typically at the most likely amount the Company expects to receive from its customers. Variable consideration is only included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized for the contract will not occur, or when the uncertainty associated with the variable consideration is resolved. The Company's contracts with customers generally require payment under normal commercial terms after delivery with payment typically required within 30 to 120 days of delivery. However, a subset of the Company’s current contracts includes significant financing components because the timing of the transfer of the underlying products and services under contract are at the customers’ discretion. For these contracts, the Company adjusts the transaction price to reflect the effects of the time value of money.

The Company generally is not subject to collecting sales tax and has made an accounting policy election to exclude from the transaction price any sales and other similar taxes collected from customers. As a result, any such collections are accounted for on a net basis.

The total transaction price is allocated to each of the identified performance obligations using the relative stand-alone selling price. The objective of the allocation is to reflect the consideration that the Company expects to receive in exchange for the products or services associated with each performance obligation. Stand-alone selling price is the price at which the Company would sell a promised good or service separately to a customer. Stand-alone selling prices are established at contract inception, and subsequent changes in transaction price are allocated on the same basis as at contract inception. When stand-alone selling prices for the Company’s products and services are not observable, the Company uses either the “Expected Cost Plus a Margin” or "Adjusted Market Assessment" approaches to estimate stand-alone selling price. Expected costs are typically derived from the available periodic forecast information.

Revenue is recognized when or as control of promised products or services transfers to a customer and is recognized at the amount allocated to each performance obligation associated with the transferred products or services. Service sales, principally representing repair, maintenance, and engineering activities are recognized over the contractual period or as services are rendered. Sales under long-term contracts with performance obligations satisfied over time are recognized using either an input or output method. The Company recognizes revenue over time as it performs on these contracts because of the continuous transfer of control to the customer as represented by contractual terms that entitle the Company to the reimbursement of costs plus a reasonable profit for work performed to manufacture products for which the Company has no alternate use or for work performed on a customer-owned asset.

With control transferring over time, revenue is recognized based on the extent of progress toward completion of the performance obligation. The Company generally uses the cost-to-cost input method of progress for its contracts because it best depicts the transfer of control to the customer that occurs as work progresses. Under the cost-to-cost method, the extent of progress toward completion is measured based on the proportion of costs incurred to date to the total estimated costs at completion of the performance obligation. The Company reviews its cost estimates on contracts on a periodic basis, or when circumstances change

and warrant a modification to a previous estimate. Cost estimates are largely based on negotiated or estimated purchase contract terms, historical performance trends and other economic projections. Significant factors that influence these estimates include inflationary trends, technical and schedule risk, internal and subcontractor performance trends, business volume assumptions, asset utilization, and anticipated labor agreements.

Revenue and cost estimates are regularly monitored and revised based on changes in circumstances. Impacts from changes in estimates of net sales and cost of sales are recognized on a cumulative catch-up basis, which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a performance obligation’s percentage of completion. Forward loss reserves for anticipated losses on long-term contracts are recorded in full when such losses become evident, to the extent required, and are included in contract liabilities on the accompanying condensed consolidated balance sheets. The Company believes that the accounting estimates and assumptions made by management are appropriate given the increased uncertainties surrounding the severity and duration of the impacts of the COVID-19 pandemic; however, actual results could differ materially from those estimates.

For the three months ended June 30, 2021, cumulative catch-up adjustments resulting from changes in contract values and estimated costs that arose during the fiscal year increased net sales by approximately $8,737 and decreased operating loss, net loss, and loss per share by approximately $14,937, $14,937, and $0.23, respectively. For the three months ended June 30, 2020, cumulative catch-up adjustments resulting from changes in estimates increased revenue by approximately $1,560 and decreased operating loss, net loss, and loss per share by approximately $3,326, $3,326, and $0.06, respectively.

Revenues for performance obligations that are not recognized over time are recognized at the point in time when control transfers to the customer. For performance obligations that are satisfied at a point in time, the Company evaluates the point in time when the customer can direct the use of and obtain the benefits from the products and services. Generally, the shipping terms determine the point in time when control transfers to customers. Shipping and handling activities are not considered performance obligations and related costs are included in cost of sales as incurred.

Differences in the timing of revenue recognition and contractual billing and payment terms result in the recognition contract assets and liabilities. Refer to Note 4 for further discussion.

In connection with several prior acquisitions, the Company assumed existing long-term contracts. Based on review of these contracts at the acquisition date, the Company concluded that the terms of certain contracts were either more or less favorable than could be realized in market transactions as of the date of the acquisition. As a result, the Company recognized acquired contract liabilities, net of acquired contract assets as of the acquisition date of each respective acquisition, based on the present value of the difference between the contractual cash flows of the executory contracts and the estimated cash flows had the contracts been executed at the acquisition date. The liabilities principally relate to long-term contracts that were initially executed several years prior to the respective acquisition. The Company measured these net liabilities in the year they were acquired under the measurement provisions of Accounting Standards Codification (“ASC”) 820, Fair Value Measurement, which is based on the price to transfer the obligation to a market participant at the measurement date, assuming that the net liabilities will remain outstanding in the marketplace. The portion of the Company's revenue resulting from transactions other than contracts with customers pertains to the amortization of these acquired contract liabilities as the related contractual performance obligations are satisfied. Adjustments to these liabilities due to significant changes in the total estimated costs of the contract are accounted for in a manner consistent with other loss contract reserves, with such adjustments recognized in cost of sales.