Basis of Presentation	9 Months Ended
Basis of Presentation	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial reporting and the instructions to Form 10-Q and, therefore, reflect all adjustments which are, in the opinion of management, necessary for a fair statement of the results for the interim periods presented. All such adjustments are of a normal recurring nature. These interim condensed consolidated financial statements should be read in conjunction with the Consolidated Financial Statements and Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2018. Recent Accounting Pronouncements - Not Yet Adopted Disclosure Requirements for Defined Benefit Plans In August 2018, the Financial Accounting Standards Board (“FASB”) issued amended guidance to add, remove, and clarify disclosure requirements related to defined benefit pension and other postretirement plans. The amended guidance removes the requirements to disclose: amounts in accumulated other comprehensive income (loss) expected to be recognized as components of net periodic benefit cost over the next fiscal year; the amount and timing of plan assets expected to be returned to the entity; and the effects of a one-percentage point change in assumed health care cost trend rates. The amended guidance requires disclosure of an explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. This guidance is effective for fiscal years ending after December 15, 2020, with early adoption permitted. The amended guidance is required to be applied on a retrospective basis to all periods presented. We are currently evaluating this guidance to determine the impact on our disclosures. 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. We do not expect that the amended guidance will have a material effect on our consolidated financial statements and related disclosures when we adopt this standard effective January 1, 2020. Recent Accounting Pronouncements - Adopted Codification Updates to SEC Sections In July 2019, we adopted the FASB issued guidance related to codification updates to SEC sections. The amended guidance clarifies or improves the disclosure and presentation requirements of a variety of codification topics by aligning them with the SEC’s regulations, thereby eliminating redundancies and making the codification easier to apply. While most of the amendments in this update eliminate outdated or duplicative disclosure requirements, the final rule amends the interim financial statement requirements to include a reconciliation of changes in stockholders’ equity in the notes to the financial statements or as a separate statement for each period for which an income statement is required to be filed. We have provided this required supplemental information in Note 6, “Changes in Equity and Accumulated Other Comprehensive Loss.” 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 leases with an initial term of twelve months or less and amends disclosure requirements associated with leasing arrangements. On January 1, 2019, we adopted Accounting Standards Codification (“ASC”) 842, “Leases” (“the new standard” or “ASC 842”) using the modified retrospective method. Under this method, we elected to apply the new standard as of the application date. Results for reporting periods beginning after January 1, 2019 are presented under ASC 842, while prior period amounts continue to be reported under ASC 840, “Leases” (“ASC 840”). We elected to apply the package of practical expedients permitted within the new standard, which among other things, allows us to carryforward the historical lease classification. No other transition practical expedients were elected. We implemented a new system, processes, and controls to enable the preparation of financial information upon adoption. The adoption of the new standard primarily impacted our accounting for operating leases which resulted in the recognition of right-of-use assets and corresponding lease liabilities. The accounting for finance leases did not substantially change under the new standard, and we do not have significant finance leases. Upon adoption, we established a right-of-use asset of $109.1 million (included in Other assets) and a lease liability of $110.4 million (included in Accrued liabilities and Other liabilities) at January 1, 2019. Our prospective adoption of this new standard did not result in a cumulative-effect adjustment to retained earnings. The new standard did not impact our consolidated statements of operations or consolidated statements of cash flows.