New Accounting Standards	12 Months Ended
Dec. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Standards	New Accounting Standards Revenue Recognition (Topic 606): Revenue from Contracts with Customers In July 2015, the FASB approved a one-year deferral of the effective date of ASU 2014-09, which becomes effective for the company January 1, 2018. The standard provides a single comprehensive revenue recognition model for contracts with customers, eliminates most industry-specific revenue recognition guidance, and expands disclosure requirements. The company has elected to adopt the standard using the modified retrospective transition method. "Sales and Other Operating Revenues” on the Consolidated Statement of Income includes excise, value-added and similar taxes on sales transactions. Upon adoption of the standard, revenue will exclude sales-based taxes collected on behalf of third parties, which will have no impact to earnings. The company completed its accounting policy and system enhancements necessary to meet the standard's requirements. The company does not expect the implementation of the standard to have a material effect on its consolidated financial statements. Leases (Topic 842) In February 2016, the FASB issued ASU 2016-02, which becomes effective for the company January 1, 2019. The standard requires that lessees present right-of-use assets and lease liabilities on the balance sheet. The company's implementation efforts are focused on accounting policy and disclosure updates and system enhancements necessary to meet the standard's requirements. The company is evaluating the effect of the standard on the company’s consolidated financial statements. Financial Instruments - Credit Losses (Topic 326) In June 2016, the FASB issued ASU 2016-13, which becomes effective for the company beginning January 1, 2020. The standard requires companies to use forward-looking information to calculate credit loss estimates. The company is evaluating the effect of the standard on the company’s consolidated financial statements. Intangibles - Goodwill and Other (Topic 350) In January 2017, the FASB issued ASU 2017-04. The standard simplifies the accounting for goodwill impairment, and the company has chosen to early adopt beginning January 1, 2017. Early adoption has no effect on the company's consolidated financial statements. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) In March 2017, the FASB issued ASU 2017-05, which becomes effective for the company January 1, 2018. The standard provides clarification regarding the guidance on accounting for the derecognition of nonfinancial assets. The company does not expect the implementation of the standard to have a material effect on its consolidated financial statements. Compensation - Retirement Benefits (Topic 715) In March 2017, the FASB issued ASU 2017-07, which becomes effective for the company January 1, 2018. The standard requires the disaggregation of the service cost component from the other components of net periodic benefit cost and allows only the service cost component of net benefit cost to be eligible for capitalization. The company does not expect the implementation of the standard to have a material effect on its consolidated financial statements. Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU 2016-15, which becomes effective for the company January 1, 2018 on a retrospective basis. The standard provides clarification on how certain cash receipts and cash payments are presented and classified on the statement of cash flows. The company does not expect the adoption of this ASU to have a material impact on its Consolidated Statement of Cash Flows. Statement of Cash Flows (Topic 230) Restricted Cash In November 2016, the FASB issued ASU 2016-18, which becomes effective for the company January 1, 2018 on a retrospective basis. The standard requires an entity to explain the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents on the statement of cash flows and to provide a reconciliation to the balance sheet when the cash, cash equivalents, restricted cash and restricted cash equivalents are not separately presented or are presented in more than one line item on the balance sheet. Upon adoption, the company’s restricted cash balances will be included in the beginning and ending balances on the Consolidated Statement of Cash Flows.

New Accounting Standards

Revenue Recognition (Topic 606): Revenue from Contracts with Customers In July 2015, the FASB approved a one-year deferral of the effective date of ASU 2014-09, which becomes effective for the company January 1, 2018. The standard provides a single comprehensive revenue recognition model for contracts with customers, eliminates most industry-specific revenue recognition guidance, and expands disclosure requirements. The company has elected to adopt the standard using the modified retrospective transition method. "Sales and Other Operating Revenues” on the Consolidated Statement of Income includes excise, value-added and similar taxes on sales transactions. Upon adoption of the standard, revenue will exclude sales-based taxes collected on behalf of third parties, which will have no impact to earnings. The company completed its accounting policy and system enhancements necessary to meet the standard's requirements. The company does not expect the implementation of the standard to have a material effect on its consolidated financial statements.

Leases (Topic 842) In February 2016, the FASB issued ASU 2016-02, which becomes effective for the company January 1, 2019. The standard requires that lessees present right-of-use assets and lease liabilities on the balance sheet. The company's implementation efforts are focused on accounting policy and disclosure updates and system enhancements necessary to meet the standard's requirements. The company is evaluating the effect of the standard on the company’s consolidated financial statements.

Financial Instruments - Credit Losses (Topic 326) In June 2016, the FASB issued ASU 2016-13, which becomes effective for the company beginning January 1, 2020. The standard requires companies to use forward-looking information to calculate credit loss estimates. The company is evaluating the effect of the standard on the company’s consolidated financial statements.

Intangibles - Goodwill and Other (Topic 350) In January 2017, the FASB issued ASU 2017-04. The standard simplifies the accounting for goodwill impairment, and the company has chosen to early adopt beginning January 1, 2017. Early adoption has no effect on the company's consolidated financial statements.

Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) In March 2017, the FASB issued ASU 2017-05, which becomes effective for the company January 1, 2018. The standard provides clarification regarding the guidance on accounting for the derecognition of nonfinancial assets. The company does not expect the implementation of the standard to have a material effect on its consolidated financial statements.

Compensation - Retirement Benefits (Topic 715) In March 2017, the FASB issued ASU 2017-07, which becomes effective for the company January 1, 2018. The standard requires the disaggregation of the service cost component from the other components of net periodic benefit cost and allows only the service cost component of net benefit cost to be eligible for capitalization. The company does not expect the implementation of the standard to have a material effect on its consolidated financial statements.

Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU 2016-15, which becomes effective for the company January 1, 2018 on a retrospective basis. The standard provides clarification on how certain cash receipts and cash payments are presented and classified on the statement of cash flows. The company does not expect the adoption of this ASU to have a material impact on its Consolidated Statement of Cash Flows.

Statement of Cash Flows (Topic 230) Restricted Cash In November 2016, the FASB issued ASU 2016-18, which becomes effective for the company January 1, 2018 on a retrospective basis. The standard requires an entity to explain the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents on the statement of cash flows and to provide a reconciliation to the balance sheet when the cash, cash equivalents, restricted cash and restricted cash equivalents are not separately presented or are presented in more than one line item on the balance sheet. Upon adoption, the company’s restricted cash balances will be included in the beginning and ending balances on the Consolidated Statement of Cash Flows.