Basis of Presentation Basis of Presentation (Policies)	6 Months Ended
Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements - Not Yet Adopted Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the Financial Accounting Standard Board (“FASB”) issued amended guidance to allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (“TCJA”). This amended guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating whether to adopt the amended guidance and, if so, the impact that it will have on its consolidated financial statements. Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued amended guidance that changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans and other instruments, entities will be required to use a new forward-looking “expected loss” model that will replace today’s “incurred loss” model and generally will result in the earlier recognition of allowances for losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses in a manner similar to current practice, except that the losses will be recognized as an allowance. This amended guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Entities will apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first effective reporting period. The Company does not expect that the amended guidance will have a material effect on its consolidated financial statements and related disclosures. Leases In February 2016, the FASB issued amended guidance on accounting for leases. The amended guidance requires the recognition of a right-of-use asset and a lease liability for all leases by lessees with the exception of short-term leases and amends disclosure requirements associated with leasing arrangements. The new standard is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2018 using a modified retrospective transition approach. The Company expects to adopt this standard as of January 1, 2019. The Company has formed an implementation team to evaluate the effect of the new guidance on its financial statements and related disclosures and is in the process of implementing a solution to facilitate the development of business processes and controls around leases to meet the new accounting and disclosure requirements upon adoption in the first quarter of 2019. Recent Accounting Pronouncements - Adopted Revenue Recognition In May 2014, the FASB issued new accounting guidance related to revenue recognition - Accounting Standards Codification (“ASC”) Topic 606, “Revenue from Contracts with Customers” (“the new standard” or “ASC 606”). The new standard replaced all current U.S. GAAP guidance on revenue recognition and eliminates all industry-specific guidance. ASC 606 provides a unified model to determine when and how revenue is recognized. The core principle is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method. The Company elected to use the practical expedient and applied ASC 606 only to contracts that were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts continue to be reported under ASC Topic 605, “Revenue Recognition”. The Company recognized the cumulative effect of initially applying ASC 606 as a net addition of $6.7 million to the opening balance of retained earnings at January 1, 2018. Upon adoption, the Company established a contract asset of $28.1 million ($22.1 million net of advanced payments received for the same contracts) and a deferred tax liability of $2.3 million and reduced inventories by $19.1 million at January 1, 2018. The accounting change relates primarily to products that are customized or products sold directly to the U.S. government or indirectly to the U.S. government through subcontracts. Revenue for such products is now recognized over time because control is transferred continuously to customers, as the contract progresses. To measure progress in these contracts, the Company applies a cost-to-cost methodology which serves as the basis to determine the amount of revenue to recognize. Prior to the adoption of ASC 606, the Company recognized revenue for these products at a point in time - either upon shipment or delivery - based on the specific shipping terms in the contract. For the three and six months ended June 30, 2018, the impact to revenues was an increase of $6.2 million and $18.6 million, respectively, and the impact to cost of sales was an increase of $2.4 million and $12.1 million, respectively, as a result of applying ASC 606. As of June 30, 2018, the effect of this change decreased inventories by $40.1 million and increased other current assets by $53.3 million due to the recognition of contract assets for unbilled amounts related to contracts for customized products or contracts for products sold directly to the U.S. government or indirectly to the U.S. government through subcontracts. Advanced payments from customers represent contract liabilities as defined by ASC 606. As such, in Note 11, “Accrued liabilities”, the line “Advanced payments from customers” is now “Contract liabilities”. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March 2017, the FASB issued amended guidance related to the presentation of net periodic pension cost and net periodic postretirement benefit cost. The amended guidance requires the disaggregation of the service cost component from the other components of net periodic benefit costs and present it with other current compensation costs for related employees in the income statement, and present the other components elsewhere in the income statement and outside of income from operations if that subtotal is presented. This amended guidance was effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted the guidance on January 1, 2018 using the retrospective method. The Company applied the practical expedient that allows the use of the pension and postretirement benefit plan disclosures for the prior comparative periods to estimate amounts for retrospective application. The adoption of this guidance resulted in a reclassification of the non-service cost components of net benefit cost from cost of sales and selling, general and administrative expenses to miscellaneous income of $5.2 million and $3.3 million for the three months ended June 30, 2018 and 2017, respectively, and $10.4 million and $6.7 million for the six months ended June 30, 2018 and 2017, respectively. The adoption of this guidance did not impact consolidated net income, the consolidated balance sheets or consolidated statements of cash flows. Restricted Cash In November 2016, the FASB issued amended guidance to address diversity in the classification and presentation of changes in restricted cash on the statement of cash flows. The amended guidance requires restricted cash and restricted cash equivalents to be classified in the statements of cash flows as cash and cash equivalents. This amended guidance was effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, using a retrospective transition method. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have an impact on the Company’s consolidated statements of cash flows. Income Taxes on Intra-Entity Transfers of Assets In October 2016, the FASB issued amended guidance related to the recognition of income taxes resulting from intra-entity transfers of assets other than inventory. The guidance requires companies to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Income tax effects of intra-entity transfers of inventory will continue to be deferred until the inventory has been sold to a third party. This amended guidance was effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods, using a modified retrospective approach, with the cumulative effect recognized through retained earnings at the date of adoption. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. Cash Flow Simplification In August 2016, the FASB issued amended guidance that clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. The amended guidance was effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have an impact on the Company’s consolidated statements of cash flows. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued amended guidance on the classification and measurement of financial instruments, including significant revisions in accounting related to the classification and measurement of investments in equity securities and presentation of certain fair value changes for financial liabilities when the fair value option is elected. The amended guidance requires equity securities to be measured at fair value with changes in fair value recognized through net earnings and amends certain disclosure requirements associated with the fair value of financial instruments. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. Other Recently Issued Pronouncements On December 22, 2017, the U.S. Securities and Exchange Commission (“SEC”) released Staff Accounting Bulletin No. 118 (“SAB 118”) which allows registrants that do not have the necessary information available, prepared, or analyzed to complete the accounting for the TCJA to report provisional amounts in their SEC filings based on reasonable estimates. Further, it provides a one year measurement period for registrants to complete their accounting for the TCJA. If provisional amounts are recorded, SAB 118 requires registrants to include additional qualitative and quantitative disclosures in their SEC filings. Further, SAB 118 requires companies to disclose the nature and amount of measurement period adjustments recognized during the reporting period and the effect of measurement period adjustments on the effective tax rate. The TCJA includes provisions effective beginning on January 1, 2018, which include a tax on 50% of global intangible low-taxed income (“GILTI”), which is income determined to be in excess of a specified routine rate of return, as well as a base erosion and anti-abuse tax (“BEAT”) aimed at preventing the erosion of the U.S. tax base. The Company continues to review GILTI and BEAT provisions and expects further guidance on the application of these provisions. The Company has not yet adopted an accounting policy as to whether the Company will treat taxes on GILTI as period costs or whether the Company will recognize deferred tax assets and liabilities when basis differences exist that are expected to affect the amount of GILTI inclusion upon reversal. Included in the Company's tax provision for the three and six month periods ended June 30, 2018 are measurement period adjustments related to the TCJA. Further detail and disclosures are discussed in Note 8, “Income Taxes”.

Recent Accounting Pronouncements - Not Yet Adopted

Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income

In February 2018, the Financial Accounting Standard Board (“FASB”) issued amended guidance to allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (“TCJA”). This amended guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating whether to adopt the amended guidance and, if so, the impact that it will have on its consolidated financial statements.

Measurement of Credit Losses on Financial Instruments

In June 2016, the FASB issued amended guidance that changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans and other instruments, entities will be required to use a new forward-looking “expected loss” model that will replace today’s “incurred loss” model and generally will result in the earlier recognition of allowances for losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses in a manner similar to current practice, except that the losses will be recognized as an allowance. This amended guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Entities will apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first effective reporting period. The Company does not expect that the amended guidance will have a material effect on its consolidated financial statements and related disclosures.

Leases

In February 2016, the FASB issued amended guidance on accounting for leases. The amended guidance requires the recognition of a right-of-use asset and a lease liability for all leases by lessees with the exception of short-term leases and amends disclosure requirements associated with leasing arrangements. The new standard is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2018 using a modified retrospective transition approach. The Company expects to adopt this standard as of January 1, 2019. The Company has formed an implementation team to evaluate the effect of the new guidance on its financial statements and related disclosures and is in the process of implementing a solution to facilitate the development of business processes and controls around leases to meet the new accounting and disclosure requirements upon adoption in the first quarter of 2019.

Recent Accounting Pronouncements - Adopted

Revenue Recognition

In May 2014, the FASB issued new accounting guidance related to revenue recognition - Accounting Standards Codification (“ASC”) Topic 606, “Revenue from Contracts with Customers” (“the new standard” or “ASC 606”). The new standard replaced all current U.S. GAAP guidance on revenue recognition and eliminates all industry-specific guidance. ASC 606 provides a unified model to determine when and how revenue is recognized. The core principle is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.

On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method. The Company elected to use the practical expedient and applied ASC 606 only to contracts that were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts continue to be reported under ASC Topic 605, “Revenue Recognition”. The Company recognized the cumulative effect of initially applying ASC 606 as a net addition of $6.7 million to the opening balance of retained earnings at January 1, 2018. Upon adoption, the Company established a contract asset of $28.1 million ($22.1 million net of advanced payments received for the same contracts) and a deferred tax liability of $2.3 million and reduced inventories by $19.1 million at January 1, 2018.

The accounting change relates primarily to products that are customized or products sold directly to the U.S. government or indirectly to the U.S. government through subcontracts. Revenue for such products is now recognized over time because control is transferred continuously to customers, as the contract progresses. To measure progress in these contracts, the Company applies a cost-to-cost methodology which serves as the basis to determine the amount of revenue to recognize. Prior to the adoption of ASC 606, the Company recognized revenue for these products at a point in time - either upon shipment or delivery - based on the specific shipping terms in the contract. For the three and six months ended June 30, 2018, the impact to revenues was an increase of $6.2 million and $18.6 million, respectively, and the impact to cost of sales was an increase of $2.4 million and $12.1 million, respectively, as a result of applying ASC 606. As of June 30, 2018, the effect of this change decreased inventories by $40.1 million and increased other current assets by $53.3 million due to the recognition of contract assets for unbilled amounts related to contracts for customized products or contracts for products sold directly to the U.S. government or indirectly to the U.S. government through subcontracts. Advanced payments from customers represent contract liabilities as defined by ASC 606. As such, in Note 11, “Accrued liabilities”, the line “Advanced payments from customers” is now “Contract liabilities”.

Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost

In March 2017, the FASB issued amended guidance related to the presentation of net periodic pension cost and net periodic postretirement benefit cost. The amended guidance requires the disaggregation of the service cost component from the other components of net periodic benefit costs and present it with other current compensation costs for related employees in the income statement, and present the other components elsewhere in the income statement and outside of income from operations if that subtotal is presented. This amended guidance was effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted the guidance on January 1, 2018 using the retrospective method. The Company applied the practical expedient that allows the use of the pension and postretirement benefit plan disclosures for the prior comparative periods to estimate amounts for retrospective application. The adoption of this guidance resulted in a reclassification of the non-service cost components of net benefit cost from cost of sales and selling, general and administrative expenses to miscellaneous income of $5.2 million and $3.3 million for the three months ended June 30, 2018 and 2017, respectively, and $10.4 million and $6.7 million for the six months ended June 30, 2018 and 2017, respectively. The adoption of this guidance did not impact consolidated net income, the consolidated balance sheets or consolidated statements of cash flows.

Restricted Cash

In November 2016, the FASB issued amended guidance to address diversity in the classification and presentation of changes in restricted cash on the statement of cash flows. The amended guidance requires restricted cash and restricted cash equivalents to be classified in the statements of cash flows as cash and cash equivalents. This amended guidance was effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, using a retrospective transition method. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have an impact on the Company’s consolidated statements of cash flows.

Income Taxes on Intra-Entity Transfers of Assets

In October 2016, the FASB issued amended guidance related to the recognition of income taxes resulting from intra-entity transfers of assets other than inventory. The guidance requires companies to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Income tax effects of intra-entity transfers of inventory will continue to be deferred until the inventory has been sold to a third party. This amended guidance was effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods, using a modified retrospective approach, with the cumulative effect recognized through retained earnings at the date of adoption. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.

Cash Flow Simplification

In August 2016, the FASB issued amended guidance that clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. The amended guidance was effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have an impact on the Company’s consolidated statements of cash flows.

Recognition and Measurement of Financial Assets and Financial Liabilities

In January 2016, the FASB issued amended guidance on the classification and measurement of financial instruments, including significant revisions in accounting related to the classification and measurement of investments in equity securities and presentation of certain fair value changes for financial liabilities when the fair value option is elected. The amended guidance requires equity securities to be measured at fair value with changes in fair value recognized through net earnings and amends certain disclosure requirements associated with the fair value of financial instruments. The Company adopted the guidance on January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.

Other Recently Issued Pronouncements

On December 22, 2017, the U.S. Securities and Exchange Commission (“SEC”) released Staff Accounting Bulletin No. 118 (“SAB 118”) which allows registrants that do not have the necessary information available, prepared, or analyzed to complete the accounting for the TCJA to report provisional amounts in their SEC filings based on reasonable estimates. Further, it provides a one year measurement period for registrants to complete their accounting for the TCJA. If provisional amounts are recorded, SAB 118 requires registrants to include additional qualitative and quantitative disclosures in their SEC filings. Further, SAB 118 requires companies to disclose the nature and amount of measurement period adjustments recognized during the reporting period and the effect of measurement period adjustments on the effective tax rate.

The TCJA includes provisions effective beginning on January 1, 2018, which include a tax on 50% of global intangible low-taxed income (“GILTI”), which is income determined to be in excess of a specified routine rate of return, as well as a base erosion and anti-abuse tax (“BEAT”) aimed at preventing the erosion of the U.S. tax base. The Company continues to review GILTI and BEAT provisions and expects further guidance on the application of these provisions. The Company has not yet adopted an accounting policy as to whether the Company will treat taxes on GILTI as period costs or whether the Company will recognize deferred tax assets and liabilities when basis differences exist that are expected to affect the amount of GILTI inclusion upon reversal.

Included in the Company's tax provision for the three and six month periods ended June 30, 2018 are measurement period adjustments related to the TCJA. Further detail and disclosures are discussed in Note 8, “Income Taxes”.