Norfolk Southern (NSC) 10-K 5 Feb 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	NORFOLK SOUTHERN CORP
Entity Central Index Key	702,165
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		283,997,242
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 35,044,199,563

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Railway operating revenues	$ 10,551	$ 9,888	$ 10,511
Railway operating expenses:
Compensation and benefits	2,915	2,743	2,911
Purchased services and rents	1,414	1,548	1,752
Fuel	840	698	934
Depreciation	1,055	1,026	1,054
Materials and other	741	799	976
Total railway operating expenses	6,965	6,814	7,627
Income from railway operations	3,586	3,074	2,884
Other income – net	92	71	103
Interest expense on debt	550	563	545
Income before income taxes	3,128	2,582	2,442
Income taxes	(2,276)	914	886
Net income	$ 5,404	$ 1,668	$ 1,556
Per share amounts:
Basic (in dollars per share)	$ 18.76	$ 5.66	$ 5.13
Diluted (in dollars per share)	$ 18.61	$ 5.62	$ 5.10

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 3,968	$ 506	$ 497	$ 433	$ 416	$ 460	$ 405	$ 387	$ 5,404	$ 1,668	$ 1,556
Other comprehensive income (loss), before tax:
Pension and other postretirement benefits									155	(74)	(76)
Other comprehensive income (loss), before tax									174	(69)	(76)
Income tax benefit (expense) related to items of other comprehensive income (loss)									(43)	27	29
Other comprehensive income (loss), net of tax									131	(42)	(47)
Total comprehensive income									5,535	1,626	1,509
Accumulated Other Comprehensive Loss Equity Investees
Other comprehensive income (loss), before tax:
Other comprehensive income (loss), before tax									19	$ 5	$ 0
Income tax benefit (expense) related to items of other comprehensive income (loss)									(2)
Other comprehensive income (loss), net of tax									$ 17

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 690	$ 956
Accounts receivable – net	955	945
Materials and supplies	222	257
Other current assets	282	133
Total current assets	2,149	2,291
Investments	2,981	2,777
Properties less accumulated depreciation of $11,909 and $11,737 respectively	30,330	29,751
Other assets	251	73
Total assets	35,711	34,892
Liabilities and stockholders’ equity
Accounts payable	1,401	1,215
Short-term debt	100	100
Income and other taxes	211	245
Other current liabilities	233	229
Current maturities of long-term debt	600	550
Total current liabilities	2,545	2,339
Long-term debt	9,136	9,562
Other liabilities	1,347	1,442
Deferred income taxes	6,324	9,140
Total liabilities	19,352	22,483
Stockholders’ equity:
Common stock $1.00 per share par value, 1,350,000,000 shares authorized; outstanding 284,157,187 and 290,417,610 shares, respectively, net of treasury shares	285	292
Additional paid-in capital	2,254	2,179
Accumulated other comprehensive loss	(356)	(487)
Retained income	14,176	10,425
Total stockholders’ equity	16,359	12,409
Total liabilities and stockholders’ equity	$ 35,711	$ 34,892

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Properties, accumulated depreciation	$ 11,909	$ 11,737
Common stock, par or stated value per share (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,350,000,000	1,350,000,000
Common stock, shares outstanding, net of treasury shares (in shares)	284,157,187	290,417,610

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 5,404	$ 1,668	$ 1,556
Reconciliation of net income to net cash provided by operating activities:
Depreciation	1,059	1,030	1,059
Deferred income taxes	(2,859)	227	320
Gains and losses on properties	(92)	(46)	(30)
Changes in assets and liabilities affecting operations:
Accounts receivable	(41)	23	109
Materials and supplies	35	42	(35)
Other current assets	(71)	82	192
Current liabilities other than debt	135	158	(152)
Other – net	(317)	(150)	(111)
Net cash provided by operating activities	3,253	3,034	2,908
Cash flows from investing activities:
Property additions	(1,723)	(1,887)	(2,385)
Property sales and other transactions	202	130	63
Investment purchases	(7)	(123)	(5)
Investment sales and other transactions	47	48	240
Net cash used in investing activities	(1,481)	(1,832)	(2,087)
Cash flows from financing activities:
Dividends	(703)	(695)	(713)
Common Stock transactions	89	57	12
Purchase and retirement of Common Stock	(1,012)	(803)	(1,075)
Proceeds from borrowings – net of issuance costs	290	694	1,185
Debt repayments	(702)	(600)	(102)
Net cash used in financing activities	(2,038)	(1,347)	(693)
Net increase (decrease) in cash and cash equivalents	(266)	(145)	128
Cash and cash equivalents:
At beginning of year	956	1,101	973
At end of year	690	956	1,101
Supplemental disclosures of cash flow information:
Interest (net of amounts capitalized)	528	543	518
Income taxes (net of refunds)	$ 705	$ 593	$ 386

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Income
Beginning Balance at Dec. 31, 2014	$ 12,408	$ 310	$ 2,148	$ (398)	$ 10,348
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,556				1,556
Other comprehensive income	(47)			(47)
Total comprehensive income	1,509
Dividends on Common Stock ($2.36, $2.36 and $2.44 for years ended 2015, 2016 and 2017, respectively)	(713)				(713)
Share repurchases	(1,075)	(11)	(75)		(989)
Stock-based compensation, including tax benefit ($14 for years ended 2015, respectively)	62		70		(8)
Other	(3)				(3)
Ending Balance at Dec. 31, 2015	12,188	299	2,143	(445)	10,191
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,668				1,668
Other comprehensive income	(42)			(42)
Total comprehensive income	1,626
Dividends on Common Stock ($2.36, $2.36 and $2.44 for years ended 2015, 2016 and 2017, respectively)	(695)				(695)
Share repurchases	(803)	(9)	(63)		(731)
Stock-based compensation, including tax benefit ($14 for years ended 2015, respectively)	95	2	99		(6)
Other	(2)				(2)
Ending Balance at Dec. 31, 2016	12,409	292	2,179	(487)	10,425
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,404				5,404
Other comprehensive income	131			131
Total comprehensive income	5,535
Dividends on Common Stock ($2.36, $2.36 and $2.44 for years ended 2015, 2016 and 2017, respectively)	(703)				(703)
Share repurchases	(1,012)	(8)	(59)		(945)
Stock-based compensation, including tax benefit ($14 for years ended 2015, respectively)	130	1	134		(5)
Ending Balance at Dec. 31, 2017	$ 16,359	$ 285	$ 2,254	$ (356)	$ 14,176

Consolidated Statements Of Cha8

Consolidated Statements Of Changes In Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Common stock, dividends, per share, declared (in dollars per share)	$ 2.44	$ 2.36	$ 2.36
Adjustments to additional paid in capital, income tax benefit from share-based compensation	$ 0	$ 0	$ 14

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	Summary of Significant Accounting Policies Description of Business Norfolk Southern Corporation (Norfolk Southern) is a Virginia-based holding company engaged principally in the rail transportation business, operating approximately 19,500 miles of road primarily in the East and Midwest. These consolidated financial statements include Norfolk Southern and its majority-owned and controlled subsidiaries (collectively, NS, we, us, and our). Norfolk Southern’s major subsidiary is NSR. All significant intercompany balances and transactions have been eliminated in consolidation. NSR and its railroad subsidiaries transport raw materials, intermediate products, and finished goods classified in the following commodity groups (percent of total railway operating revenues in 2017 ): intermodal ( 23% ); coal ( 17% ); chemicals ( 16% ); agriculture/consumer products/government ( 15% ); metals/construction ( 13% ); automotive ( 9% ); and, paper/clay/forest products ( 7% ). Although most of our customers are domestic, ultimate points of origination or destination for some of the products transported (particularly coal bound for export and some intermodal containers) may be outside the U.S. Approximately 80% of our railroad employees are covered by collective bargaining agreements with various labor unions. Use of Estimates The preparation of financial statements in accordance with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. We periodically review our estimates, including those related to the recoverability and useful lives of assets, as well as liabilities for litigation, environmental remediation, casualty claims, income taxes and pension and other postretirement benefits. Changes in facts and circumstances may result in revised estimates. Revenue Recognition Transportation revenue is recognized proportionally as a shipment moves from origin to destination, and related expenses are recognized as incurred. Refunds (which are primarily volume-based incentives) are recorded as a reduction to revenues on the basis of management’s best estimate of projected liability, which is based on historical activity, current shipment counts and the expectation of future activity. Switching, demurrage and other incidental service revenues are recognized when the services are performed. Cash Equivalents “Cash equivalents” are highly liquid investments purchased three months or less from maturity. Allowance for Doubtful Accounts Our allowance for doubtful accounts was $7 million at December 31, 2017 and $4 million at December 31, 2016 . To determine our allowance for doubtful accounts, we evaluate historical loss experience (which has not been significant), the characteristics of current accounts, and general economic conditions and trends. Materials and Supplies “Materials and supplies,” consisting mainly of items for maintenance of property and equipment, are stated at the lower of average cost or market. The cost of materials and supplies expected to be used in property additions or improvements is included in “Properties.” Investments Investments where we have the ability to exercise significant influence over but do not control the entity are accounted for using the equity method, whereby the investment is carried at the cost of the acquisition plus our equity in undistributed earnings or losses since acquisition. Properties “Properties” are stated principally at cost and are depreciated using the group method whereby assets with similar characteristics, use, and expected lives are grouped together in asset classes and depreciated using a composite depreciation rate. This methodology treats each asset class as a pool of resources, not as singular items. We use approximately 75 depreciable asset classes. “Depreciation” in the Consolidated Statements of Cash Flows includes both depreciation and depletion. Depreciation expense is based on our assumptions concerning expected service lives of our properties as well as the expected net salvage that will be received upon their retirement. In developing these assumptions, we utilize periodic depreciation studies that are performed by an independent outside firm of consulting engineers and approved by the STB. Our depreciation studies are conducted about every three years for equipment and every six years for track assets and other roadway property. The frequency of these studies is consistent with guidelines established by the STB. We adjust our rates based on the results of these studies and implement the changes prospectively. The studies may also indicate that the recorded amount of accumulated depreciation is deficient (or in excess) of the amount indicated by the study. Any such deficiency (or excess) is amortized as a component of depreciation expense over the remaining service lives of the affected class of property, as determined by the study. Key factors that are considered in developing average service life and salvage estimates include: • statistical analysis of historical retirement data and surviving asset records; • review of historical salvage received and current market rates; • review of our operations including expected changes in technology, customer demand, maintenance practices and asset management strategies; • review of accounting policies and assumptions; and • industry review and analysis. The composite depreciation rate for rail in high density corridors is derived based on consideration of annual gross tons as compared to the total or ultimate capacity of rail in these corridors. Our experience has shown that traffic density is a leading factor in the determination of the expected service life of rail in high density corridors. In developing the respective depreciation rate, consideration is also given to several rail characteristics including age, weight, condition (new or second hand) and type (curve or straight). We capitalize interest on major projects during the period of their construction. Expenditures, including those on leased assets, that extend an asset’s useful life or increase its utility are capitalized. Expenditures capitalized include those that are directly related to a capital project and may include materials, labor and equipment, in addition to an allocable portion of indirect costs that relate to a capital project. A significant portion of annual capital spending relates to the replacement of self-constructed assets. Removal activities occur in conjunction with replacement and are estimated based on the average percentage of time employees replacing assets spend on removal functions. Costs related to repairs and maintenance activities that do not extend an asset’s useful life or increase its utility are expensed when such repairs are performed. When depreciable operating road and equipment assets are sold or retired in the ordinary course of business, the cost of the assets, net of sale proceeds or salvage, is charged to accumulated depreciation, and no gain or loss is recognized in earnings. Actual historical cost values are retired when available, such as with most equipment assets. The use of estimates in recording the retirement of certain roadway assets is necessary based on the impracticality of tracking individual asset costs. When retiring rail, ties and ballast, we use statistical curves that indicate the relative distribution of the age of the assets retired. The historical cost of other roadway assets is estimated using a combination of inflation indices specific to the rail industry and those published by the U.S. Bureau of Labor Statistics. The indices are applied to the replacement value based on the age of the retired assets. These indices are used because they closely correlate with the costs of roadway assets. Gains and losses on disposal of operating land are included in “Materials and other” expenses. Gains and losses on disposal of nonoperating land and nonrail assets are included in “Other income – net” (Note 2) since such income is not a product of our railroad operations. A retirement is considered abnormal if it does not occur in the ordinary course of business, if it relates to disposition of a large segment of an asset class and if the retirement varies significantly from the retirement profile identified through our depreciation studies, which inherently consider the impact of normal retirements on expected service lives and depreciation rates. Gains or losses from abnormal retirements would be recognized in income from railway operations. We review the carrying amount of properties whenever events or changes in circumstances indicate that such carrying amount may not be recoverable based on future undiscounted cash flows. Assets that are deemed impaired as a result of such review are recorded at the lower of carrying amount or fair value. New Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, “ Revenue from Contracts with Customers .” This update will replace most existing revenue recognition guidance in GAAP and require an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. Freight revenue will continue to be recognized proportionally as a shipment moves from origin to destination and other revenues will be recognized as performance obligations are satisfied. We adopted the standard on January 1, 2018 using the modified retrospective transition method and the adoption did not have a material effect on our financial position and results of operations. Certain additional financial statement disclosures are required beginning with 2018 reporting, including disclosure of contract assets and contract liabilities as well as a disaggregated view of revenue, which we expect to be similar to our current disclosures within the “Railway Operating Revenues” section of Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” In February 2016, the FASB issued ASU 2016-02, “Leases.” This update, effective for our annual and interim reporting periods beginning January 1, 2019, will replace existing lease guidance in GAAP and will require lessees to recognize lease assets and lease liabilities on the balance sheet for leases greater than twelve months and disclose key information about leasing arrangements. When implemented, lessees and lessors will be required to measure and record leases at the present value of the remaining lease payments as of the beginning of the earliest period presented using a modified retrospective approach. We are currently evaluating the effects ASU 2016-02 will have on our consolidated financial statements and related disclosures. We currently disclose approximately $660 million in undiscounted operating lease obligations in our lease commitments footnote (Note 9) and we will evaluate those contracts as well as other existing arrangements to determine if they qualify for lease accounting under the new standard. We do not anticipate a material impact on our results of operations and we do not plan to adopt the standard early. In June 2016, the FASB issued ASU 2016-13, “Credit Losses - Measurement of Credit Losses on Financial Instruments,” which replaces the current incurred loss impairment method with a method that reflects expected credit losses. The new standard is effective as of January 1, 2020, and early adoption is permitted as of January 1, 2019. Because credit losses associated from our trade receivables have historically been insignificant, we do not expect this standard to have a material effect on our financial statements. In March 2017, the FASB issued ASU No. 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” This update, effective for annual and interim reporting periods beginning January 1, 2018, will require segregation of these net benefit costs between operating and non-operating expenses. Currently, we report the net benefit costs associated with our defined benefit and postretirement plans in the “Compensation and benefits” line item of the Consolidated Statements of Income, as disclosed in Note 11, “Pensions and Other Postretirement Benefits.” When the ASU is implemented, only the service cost component of defined benefit pension cost and postretirement benefit cost will be reported within compensation costs, while all other components of net benefit cost will be presented within the “Other income – net” line item on the Consolidated Statements of Income. The standard requires retrospective application, and as such the adoption of this standard will result in offsetting increases in “Compensation and benefits” expense and “Other income – net” on the Consolidated Statements of Income for all periods of 2017 and 2016, with no impact on net income. We did not adopt the standard early.

Other Income - Net

Other Income - Net	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Other Income - Net	Other Income – Net 2017 2016 2015 ($ in millions) Rental income $ 87 $ 93 $ 80 Corporate-owned life insurance – net 33 20 (1 ) Royalties from coal 19 10 19 Interest income 13 10 8 Gains from sale of properties (including joint venture sales) 13 9 55 External advisor costs — (20 ) (8 ) Nonoperating depletion and depreciation (4 ) (4 ) (5 ) Taxes on nonoperating property (11 ) (11 ) (10 ) Charitable contributions (15 ) (9 ) (9 ) Other interest expense – net (including debt exchange fees) (17 ) (6 ) (4 ) Other (26 ) (21 ) (22 ) Total $ 92 $ 71 $ 103

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the Tax Cuts and Jobs Act (“tax reform”) was signed into law. Tax reform lowered the Federal corporate tax rate from 35% to 21% and made numerous other tax law changes. GAAP requires companies to recognize the effect of tax law changes in the period of enactment. As a result, “Purchased services and rents” includes a $151 million benefit for earnings generated from reductions to net deferred tax liabilities at certain equity investees and “Income taxes” includes a $3,331 million benefit primarily due to the remeasurement of our net deferred tax liabilities to reflect the lower rate. Reasonable estimates were made based on our analysis of tax reform. These provisional amounts may be adjusted in future periods during 2018 when additional information is obtained. Additional information that may affect our provisional amounts would include further clarification and guidance on how the IRS will implement tax reform, including guidance with respect to 100% bonus depreciation on self-constructed assets, further clarification and guidance on how state taxing authorities will implement tax reform and the related effect on our state income tax returns, completion of our 2017 tax return filings, any changes made by our equity method investees, and the potential for additional guidance from the SEC or the FASB related to tax reform. 2017 2016 2015 ($ in millions) Current: Federal $ 500 $ 612 $ 505 State 83 75 61 Total current taxes 583 687 566 Deferred: Federal (2,924 ) 206 292 State 65 21 28 Total deferred taxes (2,859 ) 227 320 Income taxes $ (2,276 ) $ 914 $ 886 Reconciliation of Statutory Rate to Effective Rate “Income taxes” in the Consolidated Statements of Income differs from the amounts computed by applying the statutory federal corporate tax rate as follows: 2017 2016 2015 Amount % Amount % Amount % ($ in millions) Federal income tax at statutory rate $ 1,095 35.0 $ 904 35.0 $ 855 35.0 State income taxes, net of federal tax effect 88 2.8 70 2.8 72 3.0 Excess tax benefits on stock-based compensation (39 ) (1.2 ) (17 ) (0.7 ) — — Equity in earnings related to tax reform (38 ) (1.2 ) — — — — Other, net (51 ) (1.7 ) (43 ) (1.7 ) (41 ) (1.7 ) Tax reform (3,331 ) (106.5 ) — — — — Income taxes $ (2,276 ) (72.8 ) $ 914 35.4 $ 886 36.3 Deferred Tax Assets and Liabilities Certain items are reported in different periods for financial reporting and income tax purposes. Deferred tax assets and liabilities are recorded in recognition of these differences. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows: December 31, 2017 2016 ($ in millions) Deferred tax assets: Compensation and benefits, including postretirement benefits $ 235 $ 464 Accruals, including casualty and other claims 64 102 Other 67 62 Total gross deferred tax assets 366 628 Less valuation allowance (44 ) (39 ) Net deferred tax assets 322 589 Deferred tax liabilities: Property (6,212 ) (9,301 ) Other (434 ) (428 ) Total deferred tax liabilities (6,646 ) (9,729 ) Deferred income taxes $ (6,324 ) $ (9,140 ) Except for amounts for which a valuation allowance has been provided, we believe that it is more likely than not that the results of future operations will generate sufficient taxable income to realize the deferred tax assets. The valuation allowance at the end of each year primarily relates to subsidiary state income tax net operating losses and state investment tax credits that may not be utilized prior to their expiration. The total valuation allowance increased by $5 million in 2017 and $4 million in 2016 . Uncertain Tax Positions A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: December 31, 2017 2016 ($ in millions) Balance at beginning of year $ 27 $ 25 Additions based on tax positions related to the current year 4 3 Additions for tax positions of prior years 2 — Reductions for tax positions of prior years (2 ) — Settlements with taxing authorities (11 ) — Lapse of statutes of limitations (3 ) (1 ) Balance at end of year $ 17 $ 27 Included in the balance of unrecognized tax benefits at December 31, 2017 , are potential benefits of $11 million that would affect the effective tax rate if recognized. Unrecognized tax benefits are adjusted in the period in which new information about a tax position becomes available or the final outcome differs from the amount recorded. IRS examinations have been completed for all years prior to 2013. We have amended our 2012 income tax return to request a refund of $46 million , which is not included in the above balance of unrecognized tax benefits. State income tax returns generally are subject to examination for a period of three to four years after filing of the return. In addition, we are generally obligated to report changes in taxable income arising from federal income tax examinations to the states within a period of up to two years from the date the federal examination is final. We have various state income tax returns either under examination, administrative appeal, or litigation.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements FASB Accounting Standards Codification (ASC) 820-10, “Fair Value Measurements,” established a framework for measuring fair value and a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels, as follows: Level 1 Inputs to the valuation methodology are unadjusted quoted prices for identical assets or liabilities in active markets that we have the ability to access. Level 2 Inputs to the valuation methodology include: • quoted prices for similar assets or liabilities in active markets; • quoted prices for identical or similar assets or liabilities in inactive markets; • inputs other than quoted prices that are observable for the asset or liability; • inputs that are derived principally from or corroborated by observable market data by correlation or other means. If the asset or liability has a specified (contractual) term, the Level 2 input must be observable for substantially the full term of the asset or liability. Level 3 Inputs to the valuation methodology are unobservable and significant to the fair value measurement. The asset’s or liability’s fair value measurement level within the hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Other than those assets and liabilities described below that approximate fair value, there were no assets or liabilities measured at fair value on a recurring basis at December 31, 2017 or 2016 . Fair Values of Financial Instruments We have evaluated the fair values of financial instruments and methods used to determine those fair values. The fair values of “Cash and cash equivalents,” “Accounts receivable,” “Accounts payable,” and “Short-term debt” approximate carrying values because of the short maturity of these financial instruments. The carrying value of corporate-owned life insurance is recorded at cash surrender value and, accordingly, approximates fair value. The carrying amounts and estimated fair values for the remaining financial instruments, excluding investments accounted for under the equity method, consisted of the following at December 31: 2017 2016 Carrying Amount Fair Value Carrying Amount Fair Value ($ in millions) Long-term investments $ 26 $ 49 $ 116 $ 141 Long-term debt, including current maturities (9,736 ) (11,771 ) (10,112 ) (11,626 ) Underlying net assets and future discounted cash flows were used to estimate the fair value of investments. The fair values of long-term debt were estimated based on quoted market prices or discounted cash flows using current interest rates for debt with similar terms, credit rating, and remaining maturity. The following tables set forth the fair value of long-term investment and long-term debt balances disclosed above by valuation technique level, within the fair value hierarchy (there were no level 3 valued assets or liabilities). Level 1 Level 2 Total ($ in millions) December 31, 2017 Long-term investments $ 4 $ 45 $ 49 Long-term debt, including current maturities (11,676 ) (95 ) (11,771 ) December 31, 2016 Long-term investments $ 4 $ 137 $ 141 Long-term debt, including current maturities (11,427 ) (199 ) (11,626 )

Investments

Investments	12 Months Ended
	Dec. 31, 2017
Investments [Abstract]
Investments	Investments December 31, 2017 2016 ($ in millions) Long-term investments: Equity method investments: Conrail Inc. $ 1,293 $ 1,199 TTX Company 629 471 Meridian Speedway LLC 272 274 Pan Am Southern LLC 154 155 Other 77 77 Total equity method investments 2,425 2,176 Corporate-owned life insurance at net cash surrender value 530 485 Other investments 26 116 Total long-term investments $ 2,981 $ 2,777 Investment in Conrail Through a limited liability company, we and CSX jointly own Conrail, whose primary subsidiary is CRC. We have a 58% economic and 50% voting interest in the jointly owned entity, and CSX has the remainder of the economic and voting interests. We are amortizing the excess of the purchase price over Conrail’s net equity using the principles of purchase accounting, based primarily on the estimated useful lives of Conrail’s depreciable property and equipment, including the related deferred tax effect of the differences in book and tax accounting bases for such assets, as all of the purchase price at acquisition was allocable to Conrail’s tangible assets and liabilities. At December 31, 2017 , based on the funded status of Conrail’s pension plans, we increased our proportional investment in Conrail by $19 million . This resulted in income of $17 million recorded to “Other comprehensive income” and a combined federal and state deferred tax liability of $2 million . At December 31, 2016 , based on the funded status of Conrail’s pension plans, we increased our proportional investment in Conrail by $5 million . This resulted in income of $5 million recorded to “Other comprehensive loss” and a combined federal and state deferred tax liability of less than $1 million . At December 31, 2017 , the difference between our investment in Conrail and our share of Conrail’s underlying net equity was $519 million . Our equity in the earnings of Conrail, net of amortization, included in “Purchased services and rents” was $75 million (including $33 million related to the enactment of tax reform - see Note 3) for 2017 , $47 million for 2016 , and $42 million for 2015 . Equity in earnings are included in the “Other - net” line item within operating activities in the Consolidated Statements of Cash Flows. CRC owns and operates certain properties (the Shared Assets Areas) for the joint and exclusive benefit of NSR and CSX Transportation, Inc. (CSXT). The costs of operating the Shared Assets Areas are borne by NSR and CSXT based on usage. In addition, NSR and CSXT pay CRC a fee for access to the Shared Assets Areas. “Purchased services and rents” and “Fuel” include expenses payable to CRC for operation of the Shared Assets Areas totaling $141 million in 2017 , $151 million in 2016 , and $154 million in 2015 . Future minimum lease payments due to CRC under the Shared Assets Areas agreements are as follows: $38 million in each of 2018 through 2022 and $91 million thereafter. We provide certain general and administrative support functions to Conrail, the fees for which are billed in accordance with several service-provider arrangements and approximate $8 million annually. “Accounts payable” includes $146 million at December 31, 2017 , and $129 million at December 31, 2016 , due to Conrail for the operation of the Shared Assets Areas. “Other liabilities” includes $280 million at both December 31, 2017 and 2016 for long-term advances from Conrail, maturing in 2044 , that bear interest at an average rate of 2.9% . Investment in TTX NS and eight other North American railroads jointly own TTX Company (TTX). NS has a 19.65% ownership interest in TTX, a railcar pooling company that provides its owner-railroads with standardized fleets of intermodal, automotive, and general use railcars at stated rates. Amounts paid to TTX for use of equipment are included in “Purchased services and rents.” This amounted to $237 million , $229 million , and $219 million of expense, respectively, for the years ended December 31, 2017 , 2016 and 2015 . Our equity in the earnings of TTX, also included in “Purchased services and rents,” totaled $158 million (including $115 million related to the enactment of tax reform - see Note 3) for 2017 , $26 million for 2016 , and $21 million for 2015 .

Properties

Properties	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Properties	Properties Accumulated Net Book Depreciation December 31, 2017 Cost Depreciation Value Rate (1) ($ in millions) Land $ 2,342 $ — $ 2,342 — Roadway: Rail and other track material 6,730 (1,961 ) 4,769 2.28 % Ties 5,181 (1,374 ) 3,807 3.37 % Ballast 2,654 (624 ) 2,030 2.71 % Construction in process 447 — 447 — Other roadway 13,636 (3,523 ) 10,113 2.59 % Total roadway 28,648 (7,482 ) 21,166 Equipment: Locomotives 5,658 (2,158 ) 3,500 3.77 % Freight cars 3,256 (1,286 ) 1,970 2.48 % Computers and software 610 (334 ) 276 10.61 % Construction in process 247 — 247 — Other equipment 1,004 (366 ) 638 5.06 % Total equipment 10,775 (4,144 ) 6,631 Other property 474 (283 ) 191 0.77 % Total properties $ 42,239 $ (11,909 ) $ 30,330 Accumulated Net Book Depreciation December 31, 2016 Cost Depreciation Value Rate (1) ($ in millions) Land $ 2,330 $ — $ 2,330 — Roadway: Rail and other track material 6,632 (1,997 ) 4,635 2.46 % Ties 5,011 (1,314 ) 3,697 3.25 % Ballast 2,559 (584 ) 1,975 2.64 % Construction in process 664 — 664 — Other roadway 13,096 (3,361 ) 9,735 2.51 % Total roadway 27,962 (7,256 ) 20,706 Equipment: Locomotives 5,525 (2,199 ) 3,326 3.65 % Freight cars 3,377 (1,345 ) 2,032 2.51 % Computers and software 552 (329 ) 223 10.40 % Construction in process 295 — 295 — Other equipment 972 (329 ) 643 4.71 % Total equipment 10,721 (4,202 ) 6,519 Other property 475 (279 ) 196 0.83 % Total properties $ 41,488 $ (11,737 ) $ 29,751 (1) Composite annual depreciation rate for the underlying assets, excluding the effects of the amortization of any deficiency (or excess) that resulted from our depreciation studies. Other property includes the costs of obtaining rights to natural resources of $336 million at both December 31, 2017 and December 31, 2016 , with accumulated depletion of $200 million and $199 million , respectively. Capitalized Interest Total interest cost incurred on debt was $570 million in 2017 , $583 million in 2016 , and $566 million in 2015 , of which $20 million in both 2017 and 2016 and $21 million in 2015 was capitalized.

Current Liabilities

Current Liabilities	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Current Liabilities	Current Liabilities December 31, 2017 2016 ($ in millions) Accounts payable: Accounts and wages payable $ 822 $ 650 Casualty and other claims (Note 16) 187 192 Due to Conrail (Note 5) 146 129 Vacation liability 133 134 Other 113 110 Total $ 1,401 $ 1,215 Other current liabilities: Interest payable $ 115 $ 119 Pension benefit obligations (Note 11) 17 16 Other 101 94 Total $ 233 $ 229

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt Debt with weighted average interest rates and maturities is presented below: December 31, 2017 2016 ($ in millions) Notes and debentures: 5.32% maturing to 2022 $ 2,682 $ 3,232 4.42% maturing 2023 to 2031 2,965 2,746 4.54% maturing 2037 to 2052 4,404 3,190 6.81% maturing 2097 to 2111 531 1,328 Securitization borrowings and capital leases 102 202 Discounts, premiums, and debt issuance costs (848 ) (486 ) Total debt 9,836 10,212 Less current maturities and short-term debt (700 ) (650 ) Long-term debt excluding current maturities and short-term debt $ 9,136 $ 9,562 Long-term debt maturities subsequent to 2018 are as follows: 2019 $ 585 2020 314 2021 584 2022 600 2023 and subsequent years 7,053 Total $ 9,136 During the fourth quarter of 2017, we issued $ 750 million of senior notes at 3.94% due 2047 and paid $ 52 million of premium in exchange for $ 613 million of previously issued notes ($ 241 million at 6% due 2105 , $ 208 million at 4.8% due 2043 , $ 78 million at 7.05% due 2037 , $ 49 million at 7.8% due 2027 , $ 32 million at 7.25% due 2031 and $ 5 million at 6% due 2111 ). The premium is reflected as a reduction of debt in the Consolidated Balance Sheet and within “Debt repayments” in the Consolidated Statement of Cash Flows and will be amortized as additional interest expense over the term of the new debt. No gain or loss was recognized as a result of the debt exchange. During the third quarter of 2017, we issued $ 750 million of senior notes at 4.05% due 2052 in exchange for $ 551 million of previously issued notes ($ 48 million at 7.9% due 2097 , $ 378 million at 6% due 2111 , and $ 125 million at 6% due 2105 ). No gain or loss was recognized as a result of the debt exchange. During the second quarter of 2017 , we issued $300 million of 3.15% senior notes due 2027 . We have in place a $350 million receivables securitization facility under which NSR sells substantially all of its eligible third-party receivables to a subsidiary, which in turn may transfer beneficial interests in the receivables to various commercial paper vehicles. Amounts received under the facility are accounted for as borrowings. Under this facility, we received $100 million in 2016, and paid $100 million in both 2017 and 2016. The facility expires in June 2018. At December 31, 2017 , the amount outstanding under the facility was $100 million (at an average variable interest rate of 3.21% ). Our intent is to pay the remaining balance by the June 2018 expiration, therefore, this amount was included within “Short-term debt” at December 31, 2017. At December 31, 2016, the amount outstanding was $200 million (at an average variable interest rate of 2.47% ), with $100 million included within “Long-term debt” and the remaining $100 million outstanding included in “Short-term debt” in the Consolidated Balance Sheet. At December 31, 2017 and 2016, the receivables included in “Accounts receivable-net” serving as collateral for these borrowings totaled $751 million and $704 million , respectively. These borrowings are supported by our $ 750 million credit agreement (see below). Credit Agreement and Debt Covenants We have in place and available a $750 million , five -year credit agreement which expires in May 2021 and provides for borrowings at prevailing rates and includes covenants. We had no amounts outstanding under this facility at December 31, 2017 and 2016 , and we are in compliance with all of its covenants.

Lease Commitments

Lease Commitments	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Lease Commitments	Lease Commitments We are committed under long-term lease agreements, which expire on various dates through 2067 , for equipment, lines of road and other property. The following amounts do not include payments to CRC under the Shared Assets Areas agreements (Note 5). Future minimum lease payments and operating lease expense are as follows: Future Minimum Lease Payments Operating Leases ($ in millions) 2018 $ 69 2019 66 2020 60 2021 55 2022 51 2023 and subsequent years 359 Total $ 660 Operating Lease Expense 2017 2016 2015 ($ in millions) Minimum rents $ 90 $ 98 $ 111 Contingent rents 79 73 84 Total $ 169 $ 171 $ 195 Contingent rents are primarily comprised of usage-based rent paid to other railroads for joint facility operations.

Other Liabilities

Other Liabilities	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Other Liabilities	Other Liabilities December 31, 2017 2016 ($ in millions) Net other postretirement benefit obligations (Note 11) $ 309 $ 346 Net pension benefit obligations (Note 11) 296 333 Long-term advances from Conrail (Note 5) 280 280 Casualty and other claims (Note 16) 179 178 Deferred compensation 113 112 Other 170 193 Total $ 1,347 $ 1,442

Pensions And Other Postretireme

Pensions And Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pensions And Other Postretirement Benefits	Pensions and Other Postretirement Benefits We have both funded and unfunded defined benefit pension plans covering principally salaried employees. We also provide specified health care and life insurance benefits to eligible retired employees; these plans can be amended or terminated at our option. Under our self-insured retiree health care plan, for those participants who are not Medicare-eligible, a defined percentage of health care expenses is covered for retired employees and their dependents, reduced by any deductibles, coinsurance, and, in some cases, coverage provided under other group insurance policies. Those participants who are Medicare-eligible are not covered under the self-insured retiree health care plan, but instead are provided with an employer-funded health reimbursement account which can be used for reimbursement of health insurance premiums or eligible out-of-pocket medical expenses. Pension and Other Postretirement Benefit Obligations and Plan Assets Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 ($ in millions) Change in benefit obligations: Benefit obligation at beginning of year $ 2,420 $ 2,372 $ 528 $ 536 Service cost 38 36 7 7 Interest cost 80 82 15 16 Actuarial losses 143 66 6 14 Benefits paid (140 ) (136 ) (46 ) (45 ) Benefit obligation at end of year 2,541 2,420 510 528 Change in plan assets: Fair value of plan assets at beginning of year 2,073 2,040 182 189 Actual return on plan assets 423 152 40 17 Employer contribution 1 17 17 25 21 Benefits paid (140 ) (136 ) (46 ) (45 ) Fair value of plan assets at end of year 2,373 2,073 201 182 Funded status at end of year $ (168 ) $ (347 ) $ (309 ) $ (346 ) Amounts recognized in the Consolidated Balance Sheets: Noncurrent assets $ 145 $ 2 $ — $ — Current liabilities (17 ) (16 ) — — Noncurrent liabilities (296 ) (333 ) (309 ) (346 ) Net amount recognized $ (168 ) $ (347 ) $ (309 ) $ (346 ) Amounts included in accumulated other comprehensive loss (before tax): Net loss $ 781 $ 940 $ 11 $ 30 Prior service cost (benefit) 2 3 (283 ) (307 ) 1 Norfolk Southern is eligible to receive reimbursement from the Norfolk Southern Corporation Post-Retirement Benefits Trust (Trust), and the Trust had an outstanding liability to Norfolk Southern of $1 million at December 31, 2017 and $13 million at December 31, 2016 . Our accumulated benefit obligation for our defined benefit pension plans is $2.3 billion and $2.2 billion at December 31, 2017 and December 31, 2016 , respectively. Our unfunded pension plans, included above, which in all cases have no assets, had projected benefit obligations of $313 million at December 31, 2017 and $286 million at December 31, 2016 , and had accumulated benefit obligations of $267 million and $252 million at December 31, 2017 and December 31, 2016 , respectively. Pension and Other Postretirement Benefit Cost Components 2017 2016 2015 ($ in millions) Pension benefits: Service cost $ 38 $ 36 $ 41 Interest cost 80 82 93 Expected return on plan assets (172 ) (173 ) (165 ) Amortization of net losses 51 51 65 Amortization of prior service cost 1 — — Net cost (benefit) $ (2 ) $ (4 ) $ 34 Other postretirement benefits: Service cost $ 7 $ 7 $ 7 Interest cost 15 16 21 Expected return on plan assets (15 ) (17 ) (19 ) Amortization of prior service benefit (24 ) (24 ) (24 ) Net benefit $ (17 ) $ (18 ) $ (15 ) Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income 2017 Pension Other ($ in millions) Net gain arising during the year $ (108 ) $ (19 ) Amortization of net losses (51 ) — Amortization of prior service benefit (cost) (1 ) 24 Total recognized in other comprehensive income $ (160 ) $ 5 Total recognized in net periodic cost and other comprehensive income $ (162 ) $ (12 ) Net actuarial gains arising during the year for pension and other postretirement benefits were due primarily to higher actual returns on plan assets, partially offset by a decrease in discount rate. The estimated net losses for the pension benefit plans that will be amortized from accumulated other comprehensive loss into net periodic cost over the next year are $57 million . The estimated prior service benefit for the other postretirement benefit plans that will be amortized from accumulated other comprehensive loss into net periodic benefit over the next year is $24 million . Pension and Other Postretirement Benefits Assumptions Costs for pension and other postretirement benefits are determined based on actuarial valuations that reflect appropriate assumptions as of the measurement date, ordinarily the beginning of each year. The funded status of the plans is determined using appropriate assumptions as of each year end. A summary of the major assumptions follows: 2017 2016 2015 Pension funded status: Discount rate 3.74 % 4.05 % 4.30 % Future salary increases 4.21 % 4.21 % 4.50 % Other postretirement benefits funded status: Discount rate 3.57 % 3.83 % 4.02 % Pension cost: Discount rate - service cost 4.31 % 4.64 % 3.95 % Discount rate - interest cost 3.43 % 3.51 % 3.95 % Return on assets in plans 8.25 % 8.25 % 8.25 % Future salary increases 4.21 % 4.50 % 4.50 % Other postretirement benefits cost: Discount rate - service cost 4.17 % 4.36 % 3.70 % Discount rate - interest cost 3.14 % 3.15 % 3.70 % Return on assets in plans 8.00 % 8.00 % 8.00 % Health care trend rate 6.56 % 6.30 % 6.56 % To determine the discount rates used to measure our benefit obligations, we utilize analyses in which the projected annual cash flows from the pension and other postretirement benefit plans were matched with yield curves based on an appropriate universe of high-quality corporate bonds. We use the results of the yield curve analyses to select the discount rates that match the payment streams of the benefits in these plans. Effective January 1, 2016, we began using a spot rate approach to estimate the service cost and interest cost components of net periodic benefit cost for our pension and other postretirement benefits plans rather than a single weighted-average discount rate. Health Care Cost Trend Assumptions For measurement purposes at December 31, 2017 , increases in the per capita cost of pre-Medicare covered health care benefits were assumed to be 6.3% for 2018 . It is assumed the rate will decrease gradually to an ultimate rate of 5.0% for 2023 and remain at that level thereafter. Assumed health care cost trend rates affect the amounts reported in the consolidated financial statements. To illustrate, a one-percentage point change in the assumed health care cost trend would have the following effects: One-percentage point Increase Decrease ($ in millions) Increase (decrease) in: Total service and interest cost components $ 1 $ (1 ) Postretirement benefit obligation 10 (9 ) Asset Management Ten investment firms manage our defined benefit pension plans’ assets under investment guidelines approved by our Benefits Investment Committee that is comprised of members of our management. Investments are restricted to domestic and international equity securities, domestic and international fixed income securities, and unleveraged exchange-traded options and financial futures. Limitations restrict investment concentration and use of certain derivative investments. The target asset allocation for equity is 75% of the pension plans’ assets. The fixed income portfolio is invested in the BlackRock Government/Credit Bond Index Fund. Equity investments must be in liquid securities listed on national exchanges. No investment is permitted in our securities (except through commingled pension trust funds). Our pension plans’ weighted average asset allocations, by asset category, were as follows: Percentage of plan assets at December 31, 2017 2016 Domestic equity securities 49 % 51 % International equity securities 25 % 24 % Debt securities 24 % 23 % Cash and cash equivalents 2 % 2 % Total 100 % 100 % The other postretirement benefit plan assets consist primarily of trust-owned variable life insurance policies with an asset allocation at December 31, 2017 of 61% in equity securities and 39% in debt securities compared with 67% in equity securities and 33% in debt securities at December 31, 2016 . The target asset allocation for equity is between 50% and 75% of the plan’s assets. The plans’ assumed future returns are based principally on the asset allocations and historical returns for the plans’ asset classes determined from both actual plan returns and, over longer time periods, expected market returns for those asset classes. For 2018 , we assume an 8.25% return on pension plan assets. Fair Value of Plan Assets Following is a description of the valuation methodologies used for pension plan assets measured at fair value. Common stock: Shares held by the plan at year end are valued at the official closing price as defined by the exchange or at the most recent trade price of a security at the close of the active market. Common collective trusts: The readily determinable fair value is based on the published fair value per unit of the trusts. The common collective trusts hold equity securities, fixed income securities and cash and cash equivalents. Commingled funds: The readily determinable fair value is based on the published fair value per unit of the funds. The commingled funds hold equity securities. Interest bearing cash: Short-term bills or notes are valued at an estimated price at which a dealer would pay for the security at year end using observable market-based inputs; money market funds are valued at the closing price reported on the active market on which the funds are traded. U.S. government and agencies securities: Valued at an estimated price at which a dealer would pay for a security at year end using observable market-based inputs. Inflation adjusted instruments utilize the appropriate index factor. The following table sets forth the pension plans’ assets by valuation technique level, within the fair value hierarchy (there were no level 3 valued assets). December 31, 2017 Level 1 Level 2 Total ($ in millions) Common stock $ 1,154 $ — $ 1,154 Common collective trusts: Debt securities — 562 562 International equity securities — 397 397 Commingled funds — 233 233 Interest bearing cash 23 — 23 U.S. government and agencies securities — 4 4 Total investments $ 1,177 $ 1,196 $ 2,373 December 31, 2016 Level 1 Level 2 Total ($ in millions) Common stock $ 1,142 $ — $ 1,142 Common collective trusts: Debt securities — 481 481 International equity securities — 324 324 Commingled funds — 79 79 Interest bearing cash 43 — 43 U.S. government and agencies securities — 4 4 Total investments $ 1,185 $ 888 $ 2,073 Following is a description of the valuation methodologies used for other postretirement benefit plan assets measured at fair value. Trust-owned life insurance: Valued at our share of the net assets of trust-owned life insurance issued by a major insurance company. The underlying investments of that trust consist of a U.S. stock account and a U.S. bond account but may retain cash at times as well. The U.S. stock account and U.S. bond account are valued based on readily determinable fair values. The other postretirement benefit plan assets consisted of trust-owned life insurance with fair values of $201 million and $182 million at December 31, 2017 and 2016 respectively, and are valued under level 2 of the fair value hierarchy. There were no level 1 or level 3 valued assets. Contributions and Estimated Future Benefit Payments In 2018 , we expect to contribute approximately $17 million to our unfunded pension plans for payments to pensioners and approximately $43 million to our other postretirement benefit plans for retiree health and death benefits. We do not expect to contribute to our funded pension plan in 2018 . Benefit payments, which reflect expected future service, as appropriate, are expected to be paid as follows: Pension Benefits Other Postretirement Benefits ($ in millions) 2018 $ 143 $ 42 2019 143 41 2020 143 40 2021 144 38 2022 145 37 Years 2023 – 2027 731 169 Other Postretirement Coverage Under collective bargaining agreements, Norfolk Southern and certain subsidiaries participate in a multi-employer benefit plan, which provides certain postretirement health care and life insurance benefits to eligible union employees. Premiums under this plan are expensed as incurred and totaled $44 million in 2017 , $37 million in 2016 , and $32 million in 2015 . Section 401(k) Plans Norfolk Southern and certain subsidiaries provide Section 401(k) savings plans for employees. Under the plans, we match a portion of employee contributions, subject to applicable limitations. Our matching contributions, recorded as an expense, under these plans were $23 million in 2017 and $21 million in both 2016 and 2015 .

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Under the stockholder-approved Long-Term Incentive Plan (LTIP), the Compensation Committee (Committee), which is made up of nonemployee members of the Board of Directors, or the Chief Executive Officer (when delegated authority by such Committee), may grant stock options, stock appreciation rights (SARs), restricted stock units (RSUs), restricted shares, performance share units (PSUs), and performance shares, up to a maximum of 104,125,000 shares of our Common Stock, of which 8,774,768 remain available for future grants as of December 31, 2017. The number of shares remaining for issuance under the LTIP is reduced (i) by 1 for each award granted as a stock option or stock-settled SAR, or (ii) by 1.61 for an award made in the form other than a stock option or stock-settled SAR. Under the Board-approved Thoroughbred Stock Option Plan (TSOP), the Committee may grant stock options up to a maximum of 6,000,000 shares of Common Stock. We use newly issued shares to satisfy any exercises and awards under the LTIP and the TSOP. The LTIP also permits the payment, on a current or a deferred basis and in cash or in stock, of dividend equivalents on shares of Common Stock covered by stock options, RSUs, or PSUs in an amount commensurate with regular quarterly dividends paid on Common Stock. With respect to stock options, if employment of the participant is terminated for any reason, including retirement, disability, or death, we have no further obligation to make any dividend equivalent payments. Regarding RSUs, we have no further obligation to make any dividend equivalent payments unless employment of the participant is terminated as a result of qualifying retirement or disability. Should an employee terminate employment, they are not required to forfeit dividend equivalent payments already received. Outstanding PSUs do not receive dividend equivalent payments. The Committee granted stock options, RSUs and PSUs pursuant to the LTIP and granted stock options pursuant to the TSOP for the last three years as follows: 2017 2016 2015 Granted Weighted Average Grant-Date Fair Value Granted Weighted Average Grant-Date Fair Value Granted Weighted Average Grant-Date Fair Value Stock options: LTIP 341,120 $ 37.73 694,290 $ 19.92 643,890 $ 30.35 TSOP 144,440 31.33 302,320 14.75 181,320 24.71 Total 485,560 996,610 825,210 Restricted stock units 83,330 120.16 136,250 70.44 101,470 104.23 Performance share units 300,334 88.56 1,042,628 52.75 413,770 71.66 Receipt of an LTIP award is contingent on the recipient having executed a non-compete agreement with the company. We account for our grants of stock options, RSUs, PSUs, and dividend equivalent payments in accordance with ASC 718, “ Compensation - Stock Compensation .” Accordingly, all awards result in charges to net income while dividend equivalent payments, which are all related to equity classified awards, are charged to retained income. Related compensation costs and tax benefits during the year were: 2017 2016 2015 ($ in millions) Stock-based compensation expense $ 45 $ 42 $ 42 Total tax benefit 54 31 13 Stock Options Option exercise prices will be at least the higher of (i) the average of the high and low prices at which Common Stock is traded on the grant date, or (ii) the closing price of Common Stock on the grant date. All options are subject to a vesting period of at least one year, and the term of the option will not exceed ten years. Holders of the options granted under the LTIP who remain actively employed receive cash dividend equivalent payments for four years in an amount equal to the regular quarterly dividends paid on Common Stock. Dividend equivalent payments are not made on the TSOP options. For all years, options granted under the LTIP and the TSOP may not be exercised prior to the fourth and third anniversaries of the date of grant, respectively, or if the optionee retires or dies before that anniversary date, may not be exercised before the later of one year after the grant date or the date of the optionee’s retirement or death. The fair value of each option awarded in 2017 , 2016 , and 2015 was measured on the date of grant using a binomial lattice-based option valuation model. Expected volatility is based on implied volatility from traded options on, and historical volatility of, Common Stock. Historical data is used to estimate option exercises and employee terminations within the valuation model. The average expected option term is derived from the output of the valuation model and represents the period of time that all options granted are expected to be outstanding, including the branches of the model that result in options expiring unexercised. The average risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. A dividend yield of zero was used for the LTIP options during the vesting period. For 2017 , 2016 , and 2015 , a dividend yield of 2.04% , 3.37% , and 2.27% , respectively, was used for all vested LTIP options and all TSOP options. The assumptions for the LTIP and TSOP grants for the last three years are shown in the following table: 2017 2016 2015 Average expected volatility 26 % 27 % 25 % Average risk-free interest rate 2.51 % 2.00 % 1.83 % Average expected option term LTIP 8.6 years 8.9 years 9.3 years Average expected option term TSOP 8.3 years 8.6 years 9.1 years A summary of changes in stock options is presented below: Stock Options Weighted Avg. Exercise Price Outstanding at December 31, 2016 5,554,054 $ 72.57 Granted 485,560 120.25 Exercised (1,789,939 ) 60.28 Forfeited (15,608 ) 90.05 Outstanding at December 31, 2017 4,234,067 83.17 The aggregate intrinsic value of options outstanding at December 31, 2017 , was $261 million with a weighted average remaining contractual term of 6.2 years. Of these options outstanding, 2,221,577 were exercisable and had an aggregate intrinsic value of $157 million with a weighted average exercise price of $74.06 and a weighted average remaining contractual term of 4.8 years. The following table provides information related to options exercised for the last three years: 2017 2016 2015 ($ in millions) Options exercised 1,789,939 1,466,721 589,081 Total intrinsic value $ 114 $ 60 $ 27 Cash received upon exercise 104 74 29 Related tax benefits realized 35 13 7 At December 31, 2017 , total unrecognized compensation related to options granted under the LTIP and the TSOP was $10 million , and is expected to be recognized over a weighted-average period of approximately 2.2 years. Tax benefits realized in both 2017 and 2016 are recognized in “Income taxes.” Tax benefits realized in 2015 were recognized as “Additional paid-in capital.” Restricted Stock Units RSUs granted in all three years have a five -year restriction period and will be settled through the issuance of shares of Common Stock. The RSU grants include cash dividend equivalent payments during the restriction period in an amount equal to regular quarterly dividends paid on Common Stock. 2017 2016 2015 ($ in millions) RSUs vested 137,200 175,500 166,750 Common Stock issued net of tax witholding 81,318 103,936 99,337 Related tax benefit realized $ 3 $ 1 $ 4 Tax benefits realized in both 2017 and 2016 are recognized in “Income taxes.” Tax benefits realized in 2015 were recognized as “Additional paid-in capital.” A summary of changes in RSUs is presented below: RSUs Weighted- Average Grant-Date Fair Value Nonvested at December 31, 2016 645,645 $ 80.68 Granted 83,330 120.16 Vested (137,200 ) 75.14 Forfeited (3,370 ) 108.47 Nonvested at December 31, 2017 588,405 87.40 At December 31, 2017 , total unrecognized compensation related to RSUs was $8 million , and is expected to be recognized over a weighted-average period of approximately 3.2 years. Performance Share Units PSUs provide for awards based on the achievement of certain predetermined corporate performance goals at the end of a three-year cycle and are settled through the issuance of shares of Common Stock. All PSUs will earn out based on the achievement of performance conditions and some will also earn out based on a market condition. The market condition fair value was measured on the date of grant using a Monte Carlo simulation model. 2017 2016 2015 ($ in millions) PSUs earned 171,080 406,038 236,601 Common Stock issued net of tax witholding 99,805 241,757 141,386 Related tax benefit realized $ 1 $ 3 $ 3 Tax benefits realized in both 2017 and 2016 are recognized in “Income taxes.” Tax benefits realized in 2015 were recognized as “Additional paid-in capital.” A summary of changes in PSUs is presented below: PSUs Weighted- Average Grant-Date Fair Value Balance at December 31, 2016 1,849,008 $ 61.17 Granted 300,334 88.56 Earned (171,080 ) 68.67 Unearned (226,780 ) 74.93 Forfeited (2,730 ) 58.09 Balance at December 31, 2017 1,748,752 63.36 At December 31, 2017 , total unrecognized compensation related to PSUs granted under the LTIP was $6 million , and is expected to be recognized over a weighted-average period of approximately 1.8 years. Shares Available and Issued Shares of Common Stock available for future grants and issued in connection with all features of the LTIP and the TSOP at December 31, were as follows: 2017 2016 2015 Available for future grants: LTIP 8,774,768 9,385,674 11,769,796 TSOP 410,895 544,217 832,676 Issued: LTIP 1,679,547 1,511,645 708,059 TSOP 291,515 300,769 121,745

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Common Stock Common Stock is reported net of shares held by our consolidated subsidiaries (Treasury Shares). Treasury Shares at December 31, 2017 and 2016 amounted to 20,320,777 , with a cost of $19 million at both dates. Accumulated Other Comprehensive Loss The components of “Other comprehensive income (loss)” reported in the Consolidated Statements of Comprehensive Income and changes in the cumulative balances of “Accumulated other comprehensive loss” reported in the Consolidated Balance Sheets consisted of the following: Balance at Beginning of Year Net Income (Loss) Reclassification Adjustments Balance at End of Year ($ in millions) Year ended December 31, 2017 Pensions and other postretirement liabilities $ (414 ) $ 95 $ 19 $ (300 ) Other comprehensive income of equity investees (73 ) 17 — (56 ) Accumulated other comprehensive loss $ (487 ) $ 112 $ 19 $ (356 ) Year ended December 31, 2016 Pensions and other postretirement liabilities $ (367 ) $ (64 ) $ 17 $ (414 ) Other comprehensive income of equity investees (78 ) 5 — (73 ) Accumulated other comprehensive loss $ (445 ) $ (59 ) $ 17 $ (487 ) Other Comprehensive Income (Loss) “Other comprehensive income (loss)” reported in the Consolidated Statements of Comprehensive Income consisted of the following: Pretax Amount Tax (Expense) Benefit Net-of-Tax Amount ($ in millions) Year ended December 31, 2017 Net gain (loss) arising during the year: Pensions and other postretirement benefits $ 127 $ (32 ) $ 95 Reclassification adjustments for costs included in net income 28 (9 ) 19 Subtotal 155 (41 ) 114 Other comprehensive income of equity investees 19 (2 ) 17 Other comprehensive income $ 174 $ (43 ) $ 131 Year ended December 31, 2016 Net gain (loss) arising during the year: Pensions and other postretirement benefits $ (101 ) $ 37 $ (64 ) Reclassification adjustments for costs included in net income 27 (10 ) 17 Subtotal (74 ) 27 (47 ) Other comprehensive income of equity investees 5 — 5 Other comprehensive loss $ (69 ) $ 27 $ (42 ) Year ended December 31, 2015 Net gain (loss) arising during the year: Pensions and other postretirement benefits $ (117 ) $ 45 $ (72 ) Reclassification adjustments for costs included in net income 41 (16 ) 25 Other comprehensive loss $ (76 ) $ 29 $ (47 )

Stock Repurchase Program

Stock Repurchase Program	12 Months Ended
	Dec. 31, 2017
Stock Repurchase Program [Abstract]
Stock Repurchase Program	Stock Repurchase Program We repurchased and retired 8.2 million , 9.2 million , and 11.3 million shares of Common Stock under our stock repurchase program in 2017 , 2016 , and 2015 , respectively, at a cost of $1.0 billion , $803 million , and $1.1 billion , respectively. On September 26, 2017, our Board of Directors authorized the repurchase of up to an additional 50 million shares of Common Stock through December 31, 2022. As of December 31, 2017, 56.5 million shares remain authorized for repurchase. Since the beginning of 2006, we have repurchased and retired 168.5 million shares at a total cost of $11.3 billion .

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the calculation of basic and diluted earnings per share: Basic Diluted 2017 2016 2015 2017 2016 2015 ($ in millions except per share amounts, shares in millions) Net income $ 5,404 $ 1,668 $ 1,556 $ 5,404 $ 1,668 $ 1,556 Dividend equivalent payments (4 ) (5 ) (6 ) (2 ) (4 ) (5 ) Income available to common stockholders $ 5,400 $ 1,663 $ 1,550 $ 5,402 $ 1,664 $ 1,551 Weighted-average shares outstanding 287.9 293.9 301.9 287.9 293.9 301.9 Dilutive effect of outstanding options and share-settled awards 2.4 2.1 2.5 Adjusted weighted-average shares outstanding 290.3 296.0 304.4 Earnings per share $ 18.76 $ 5.66 $ 5.13 $ 18.61 $ 5.62 $ 5.10 In each year, dividend equivalent payments were made to holders of stock options and RSUs. For purposes of computing basic earnings per share, dividend equivalent payments made to holders of stock options and RSUs were deducted from net income to determine income available to common stockholders. For purposes of computing diluted earnings per share, we evaluate on a grant-by-grant basis those stock options and RSUs receiving dividend equivalent payments under the two-class and treasury stock methods to determine which method is more dilutive for each grant. For those grants for which the two-class method was more dilutive, net income was reduced by dividend equivalent payments to determine income available to common stockholders. The dilution calculations exclude options having exercise prices exceeding the average market price of Common Stock of 0.2 million , 1.3 million , and 0.9 million for the years ended December 31, 2017 , 2016 and 2015 , respectively.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies Lawsuits We and/or certain subsidiaries are defendants in numerous lawsuits and other claims relating principally to railroad operations. When we conclude that it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated, it is accrued through a charge to earnings. While the ultimate amount of liability incurred in any of these lawsuits and claims is dependent on future developments, in our opinion, the recorded liability is adequate to cover the future payment of such liability and claims. However, the final outcome of any of these lawsuits and claims cannot be predicted with certainty, and unfavorable or unexpected outcomes could result in additional accruals that could be significant to results of operations in a particular year or quarter. Any adjustments to the recorded liability will be reflected in earnings in the periods in which such adjustments become known. One of our chemical customers, Sunbelt, filed in 2011 a rate reasonableness complaint before the STB alleging that our tariff rates for transportation of regulated movements are unreasonable. Since April 1, 2011, we have been billing and collecting amounts based on the challenged tariff rates. In 2014, the STB resolved this rate reasonableness complaint in our favor, and in June 2016, the STB resolved petitions for reconsideration. The matter remains decided in our favor; however, the findings are still subject to appeal. We believe the estimate of any reasonably possible loss will not have a material effect on our financial position, results of operations, or liquidity. With regard to rate cases, we record adjustments to revenues in the periods if and when such adjustments are probable and reasonably estimable. In 2007, various antitrust class actions filed against us and other Class I railroads in various Federal district courts regarding fuel surcharges were consolidated in the District of Columbia by the Judicial Panel on Multidistrict Litigation. In 2012, the court certified the case as a class action. The defendant railroads appealed this certification, and the Court of Appeals for the District of Columbia vacated the District Court’s decision and remanded the case for further consideration. On October 10, 2017, the District Court denied class certification; the findings are subject to appeal. We believe the allegations in the complaints are without merit and intend to vigorously defend the cases. We do not believe the outcome of these proceedings will have a material effect on our financial position, results of operations, or liquidity. Casualty Claims Casualty claims include employee personal injury and occupational claims as well as third-party claims, all exclusive of legal costs. To aid in valuing our personal injury liability and determining the amount to accrue with respect to such claims during the year, we utilize studies prepared by an independent consulting actuarial firm. Job-related personal injury and occupational claims are subject to the FELA, which is applicable only to railroads. FELA’s fault-based tort system produces results that are unpredictable and inconsistent as compared with a no-fault workers’ compensation system. The variability inherent in this system could result in actual costs being different from the liability recorded. While the ultimate amount of claims incurred is dependent on future developments, in our opinion, the recorded liability is adequate to cover the future payments of claims and is supported by the most recent actuarial study. In all cases, we record a liability when the expected loss for the claim is both probable and reasonably estimable. Employee personal injury claims – The largest component of casualties and other claims expense is employee personal injury costs. The independent actuarial firm engaged by us provides quarterly studies to aid in valuing our employee personal injury liability and estimating personal injury expense. The actuarial firm studies our historical patterns of reserving for claims and subsequent settlements, taking into account relevant outside influences. The actuarial firm uses the results of these analyses to estimate the ultimate amount of liability. We adjust the liability quarterly based upon our assessment and the results of the study. Our estimate of the liability is subject to inherent limitation given the difficulty of predicting future events such as jury decisions, court interpretations, or legislative changes. As a result, actual claim settlements may vary from the estimated liability recorded. Occupational claims – Occupational claims (including asbestosis and other respiratory diseases, as well as conditions allegedly related to repetitive motion) are often not caused by a specific accident or event but rather allegedly result from a claimed exposure over time. Many such claims are being asserted by former or retired employees, some of whom have not been employed in the rail industry for decades. The independent actuarial firm provides an estimate of the occupational claims liability based upon our history of claim filings, severity, payments, and other pertinent facts. The liability is dependent upon judgments we make as to the specific case reserves as well as judgments of the actuarial firm in the quarterly studies. The actuarial firm’s estimate of ultimate loss includes a provision for those claims that have been incurred but not reported. This provision is derived by analyzing industry data and projecting our experience. We adjust the liability quarterly based upon our assessment and the results of the study. However, it is possible that the recorded liability may not be adequate to cover the future payment of claims. Adjustments to the recorded liability are reflected in operating expenses in the periods in which such adjustments become known. Third-party claims – We record a liability for third-party claims including those for highway crossing accidents, trespasser and other injuries, automobile liability, property damage, and lading damage. The actuarial firm assists us with the calculation of potential liability for third-party claims, except lading damage, based upon our experience including the number and timing of incidents, amount of payments, settlement rates, number of open claims, and legal defenses. We adjust the liability quarterly based upon our assessment and the results of the study. Given the inherent uncertainty in regard to the ultimate outcome of third-party claims, it is possible that the actual loss may differ from the estimated liability recorded. Environmental Matters We are subject to various jurisdictions’ environmental laws and regulations. We record a liability where such liability or loss is probable and reasonably estimable. Environmental engineers regularly participate in ongoing evaluations of all known sites and in determining any necessary adjustments to liability estimates. Our Consolidated Balance Sheets include liabilities for environmental exposures of $58 million at December 31, 2017 , and $67 million at December 31, 2016 , (of which $15 million is classified as a current liability at the end of both 2017 and 2016 ). At December 31, 2017 , the liability represents our estimates of the probable cleanup, investigation, and remediation costs based on available information at 127 known locations and projects compared with 134 locations and projects at December 31, 2016 . At December 31, 2017 , 15 sites accounted for $37 million of the liability, and no individual site was considered to be material. We anticipate that much of this liability will be paid out over five years; however, some costs will be paid out over a longer period. At thirteen locations, one or more of our subsidiaries in conjunction with a number of other parties have been identified as potentially responsible parties under the Comprehensive Environmental Response, Compensation and Liability Act of 1980 or comparable state statutes that impose joint and several liability for cleanup costs. We calculate our estimated liability for these sites based on facts and legal defenses applicable to each site and not solely on the basis of the potential for joint liability. With respect to known environmental sites (whether identified by us or by the Environmental Protection Agency or comparable state authorities), estimates of our ultimate potential financial exposure for a given site or in the aggregate for all such sites can change over time because of the widely varying costs of currently available cleanup techniques, unpredictable contaminant recovery and reduction rates associated with available cleanup technologies, the likely development of new cleanup technologies, the difficulty of determining in advance the nature and full extent of contamination and each potential participant’s share of any estimated loss (and that participant’s ability to bear it), and evolving statutory and regulatory standards governing liability. The risk of incurring environmental liability, for acts and omissions, past, present, and future, is inherent in the railroad business. Some of the commodities we transport, particularly those classified as hazardous materials, pose special risks that we work diligently to reduce. In addition, several of our subsidiaries own, or have owned, land used as operating property, or which is leased and operated by others, or held for sale. Because environmental problems that are latent or undisclosed may exist on these properties, there can be no assurance that we will not incur environmental liabilities or costs with respect to one or more of them, the amount and materiality of which cannot be estimated reliably at this time. Moreover, lawsuits and claims involving these and potentially other unidentified environmental sites and matters are likely to arise from time to time. The resulting liabilities could have a significant effect on financial position, results of operations, or liquidity in a particular year or quarter. Based on our assessment of the facts and circumstances now known, we believe we have recorded the probable and reasonably estimable costs for dealing with those environmental matters of which we are aware. Further, we believe that it is unlikely that any known matters, either individually or in the aggregate, will have a material adverse effect on our financial position, results of operations, or liquidity. Insurance We obtain on behalf of ourself and our subsidiaries insurance for potential losses for third-party liability and first-party property damages. We are currently self-insured up to $50 million and above $1.1 billion ( $1.5 billion for specific perils) per occurrence and/or policy year for bodily injury and property damage to third parties and up to $25 million and above $200 million per occurrence and/or policy year for property owned by us or in our care, custody, or control. Purchase Commitments At December 31, 2017 , we had outstanding purchase commitments totaling approximately $1.1 billion for locomotives, track material, long-term service contracts, track and yard expansion projects in connection with our capital programs as well as freight cars and containers through 2022. Change-In-Control Arrangements We have compensation agreements with certain officers and key employees that become operative only upon a change in control of Norfolk Southern, as defined in those agreements. The agreements provide generally for payments based on compensation at the time of a covered individual’s involuntary or other specified termination and for certain other benefits. Indemnifications In a number of instances, we have agreed to indemnify lenders for additional costs they may bear as a result of certain changes in laws or regulations applicable to their loans. Such changes may include impositions or modifications with respect to taxes, duties, reserves, liquidity, capital adequacy, special deposits, and similar requirements relating to extensions of credit by, deposits with, or the assets or liabilities of such lenders. The nature and timing of changes in laws or regulations applicable to our financings are inherently unpredictable, and therefore our exposure in connection with the foregoing indemnifications cannot be quantified. No liability has been recorded related to these indemnifications.

Quarterly Financial Data

Quarterly Financial Data	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	NORFOLK SOUTHERN CORPORATION AND SUBSIDIARIES QUARTERLY FINANCIAL DATA (Unaudited) Three Months Ended March 31 June 30 September 30 December 31 ($ in millions, except per share amounts) 2017 Railway operating revenues $ 2,575 $ 2,637 $ 2,670 $ 2,669 Income from railway operations 773 888 911 1,014 Net income 433 497 506 3,968 Earnings per share: Basic 1.49 1.72 1.76 13.91 Diluted 1.48 1.71 1.75 13.79 2016 Railway operating revenues $ 2,420 $ 2,454 $ 2,524 $ 2,490 Income from railway operations 723 770 820 761 Net income 387 405 460 416 Earnings per share: Basic 1.30 1.37 1.56 1.43 Diluted 1.29 1.36 1.55 1.42 Note : In the fourth quarter of 2017, as a result of the enactment of tax reform, “Income from railway operations” includes a $151 million benefit and income taxes includes a $3,331 million benefit, which added $3,482 million to “Net income,” $12.21 to “Earnings per share - basic,” and $12.10 to “Earnings per share - diluted.”

Schedule II - Valuation And Qua

Schedule II - Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2016
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation And Qualifying Accounts	Schedule II Norfolk Southern Corporation and Subsidiaries Valuation and Qualifying Accounts Years ended December 31, 2015 , 2016 , and 2017 ($ in millions) Additions charged to: Beginning Balance Expenses Other Accounts Deductions Ending Balance Year ended December 31, 2015 Valuation allowance (included net in deferred tax liability) for deferred tax assets $ 33 $ 2 $ — $ — $ 35 Casualty and other claims included in other liabilities 199 66 (1) — 74 (3) 191 Current portion of casualty and other claims included in accounts payable 187 19 119 (2) 151 (4) 174 Year ended December 31, 2016 Valuation allowance (included net in deferred tax liability) for deferred tax assets $ 35 $ 4 $ — $ — $ 39 Casualty and other claims included in other liabilities 191 68 (1) — 81 (3) 178 Current portion of casualty and other claims included in accounts payable 174 25 101 (2) 108 (4) 192 Year ended December 31, 2017 Valuation allowance (included net in deferred tax liability) for deferred tax assets $ 39 $ 5 $ — $ — $ 44 Casualty and other claims included in other liabilities 178 83 (1) — 82 (3) 179 Current portion of casualty and other claims included in accounts payable 192 17 124 (2) 146 (4) 187 (1) Includes adjustments for changes in estimates for prior years’ claims. (2) Includes revenue refunds and overcharges provided through deductions from operating revenues and transfers from other accounts. (3) Payments and reclassifications to/from accounts payable. (4) Payments and reclassifications to/from other liabilities.

Summary Of Significant Accoun27

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Description of Business	Description of Business Norfolk Southern Corporation (Norfolk Southern) is a Virginia-based holding company engaged principally in the rail transportation business, operating approximately 19,500 miles of road primarily in the East and Midwest. These consolidated financial statements include Norfolk Southern and its majority-owned and controlled subsidiaries (collectively, NS, we, us, and our). Norfolk Southern’s major subsidiary is NSR. All significant intercompany balances and transactions have been eliminated in consolidation. NSR and its railroad subsidiaries transport raw materials, intermediate products, and finished goods classified in the following commodity groups (percent of total railway operating revenues in 2017 ): intermodal ( 23% ); coal ( 17% ); chemicals ( 16% ); agriculture/consumer products/government ( 15% ); metals/construction ( 13% ); automotive ( 9% ); and, paper/clay/forest products ( 7% ). Although most of our customers are domestic, ultimate points of origination or destination for some of the products transported (particularly coal bound for export and some intermodal containers) may be outside the U.S. Approximately 80% of our railroad employees are covered by collective bargaining agreements with various labor unions.
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. We periodically review our estimates, including those related to the recoverability and useful lives of assets, as well as liabilities for litigation, environmental remediation, casualty claims, income taxes and pension and other postretirement benefits. Changes in facts and circumstances may result in revised estimates.
Revenue Recognition	Revenue Recognition Transportation revenue is recognized proportionally as a shipment moves from origin to destination, and related expenses are recognized as incurred. Refunds (which are primarily volume-based incentives) are recorded as a reduction to revenues on the basis of management’s best estimate of projected liability, which is based on historical activity, current shipment counts and the expectation of future activity. Switching, demurrage and other incidental service revenues are recognized when the services are performed.
Cash Equivalents	Cash Equivalents “Cash equivalents” are highly liquid investments purchased three months or less from maturity.
Allowance For Doubtful Accounts	Allowance for Doubtful Accounts Our allowance for doubtful accounts was $7 million at December 31, 2017 and $4 million at December 31, 2016 . To determine our allowance for doubtful accounts, we evaluate historical loss experience (which has not been significant), the characteristics of current accounts, and general economic conditions and trends.
Materials And Supplies	Materials and Supplies “Materials and supplies,” consisting mainly of items for maintenance of property and equipment, are stated at the lower of average cost or market. The cost of materials and supplies expected to be used in property additions or improvements is included in “Properties.”
Investments	Investments Investments where we have the ability to exercise significant influence over but do not control the entity are accounted for using the equity method, whereby the investment is carried at the cost of the acquisition plus our equity in undistributed earnings or losses since acquisition.
Properties	Properties “Properties” are stated principally at cost and are depreciated using the group method whereby assets with similar characteristics, use, and expected lives are grouped together in asset classes and depreciated using a composite depreciation rate. This methodology treats each asset class as a pool of resources, not as singular items. We use approximately 75 depreciable asset classes. “Depreciation” in the Consolidated Statements of Cash Flows includes both depreciation and depletion. Depreciation expense is based on our assumptions concerning expected service lives of our properties as well as the expected net salvage that will be received upon their retirement. In developing these assumptions, we utilize periodic depreciation studies that are performed by an independent outside firm of consulting engineers and approved by the STB. Our depreciation studies are conducted about every three years for equipment and every six years for track assets and other roadway property. The frequency of these studies is consistent with guidelines established by the STB. We adjust our rates based on the results of these studies and implement the changes prospectively. The studies may also indicate that the recorded amount of accumulated depreciation is deficient (or in excess) of the amount indicated by the study. Any such deficiency (or excess) is amortized as a component of depreciation expense over the remaining service lives of the affected class of property, as determined by the study. Key factors that are considered in developing average service life and salvage estimates include: • statistical analysis of historical retirement data and surviving asset records; • review of historical salvage received and current market rates; • review of our operations including expected changes in technology, customer demand, maintenance practices and asset management strategies; • review of accounting policies and assumptions; and • industry review and analysis. The composite depreciation rate for rail in high density corridors is derived based on consideration of annual gross tons as compared to the total or ultimate capacity of rail in these corridors. Our experience has shown that traffic density is a leading factor in the determination of the expected service life of rail in high density corridors. In developing the respective depreciation rate, consideration is also given to several rail characteristics including age, weight, condition (new or second hand) and type (curve or straight). We capitalize interest on major projects during the period of their construction. Expenditures, including those on leased assets, that extend an asset’s useful life or increase its utility are capitalized. Expenditures capitalized include those that are directly related to a capital project and may include materials, labor and equipment, in addition to an allocable portion of indirect costs that relate to a capital project. A significant portion of annual capital spending relates to the replacement of self-constructed assets. Removal activities occur in conjunction with replacement and are estimated based on the average percentage of time employees replacing assets spend on removal functions. Costs related to repairs and maintenance activities that do not extend an asset’s useful life or increase its utility are expensed when such repairs are performed. When depreciable operating road and equipment assets are sold or retired in the ordinary course of business, the cost of the assets, net of sale proceeds or salvage, is charged to accumulated depreciation, and no gain or loss is recognized in earnings. Actual historical cost values are retired when available, such as with most equipment assets. The use of estimates in recording the retirement of certain roadway assets is necessary based on the impracticality of tracking individual asset costs. When retiring rail, ties and ballast, we use statistical curves that indicate the relative distribution of the age of the assets retired. The historical cost of other roadway assets is estimated using a combination of inflation indices specific to the rail industry and those published by the U.S. Bureau of Labor Statistics. The indices are applied to the replacement value based on the age of the retired assets. These indices are used because they closely correlate with the costs of roadway assets. Gains and losses on disposal of operating land are included in “Materials and other” expenses. Gains and losses on disposal of nonoperating land and nonrail assets are included in “Other income – net” (Note 2) since such income is not a product of our railroad operations. A retirement is considered abnormal if it does not occur in the ordinary course of business, if it relates to disposition of a large segment of an asset class and if the retirement varies significantly from the retirement profile identified through our depreciation studies, which inherently consider the impact of normal retirements on expected service lives and depreciation rates. Gains or losses from abnormal retirements would be recognized in income from railway operations. We review the carrying amount of properties whenever events or changes in circumstances indicate that such carrying amount may not be recoverable based on future undiscounted cash flows. Assets that are deemed impaired as a result of such review are recorded at the lower of carrying amount or fair value.
New Accounting Pronouncements	New Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, “ Revenue from Contracts with Customers .” This update will replace most existing revenue recognition guidance in GAAP and require an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. Freight revenue will continue to be recognized proportionally as a shipment moves from origin to destination and other revenues will be recognized as performance obligations are satisfied. We adopted the standard on January 1, 2018 using the modified retrospective transition method and the adoption did not have a material effect on our financial position and results of operations. Certain additional financial statement disclosures are required beginning with 2018 reporting, including disclosure of contract assets and contract liabilities as well as a disaggregated view of revenue, which we expect to be similar to our current disclosures within the “Railway Operating Revenues” section of Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” In February 2016, the FASB issued ASU 2016-02, “Leases.” This update, effective for our annual and interim reporting periods beginning January 1, 2019, will replace existing lease guidance in GAAP and will require lessees to recognize lease assets and lease liabilities on the balance sheet for leases greater than twelve months and disclose key information about leasing arrangements. When implemented, lessees and lessors will be required to measure and record leases at the present value of the remaining lease payments as of the beginning of the earliest period presented using a modified retrospective approach. We are currently evaluating the effects ASU 2016-02 will have on our consolidated financial statements and related disclosures. We currently disclose approximately $660 million in undiscounted operating lease obligations in our lease commitments footnote (Note 9) and we will evaluate those contracts as well as other existing arrangements to determine if they qualify for lease accounting under the new standard. We do not anticipate a material impact on our results of operations and we do not plan to adopt the standard early. In June 2016, the FASB issued ASU 2016-13, “Credit Losses - Measurement of Credit Losses on Financial Instruments,” which replaces the current incurred loss impairment method with a method that reflects expected credit losses. The new standard is effective as of January 1, 2020, and early adoption is permitted as of January 1, 2019. Because credit losses associated from our trade receivables have historically been insignificant, we do not expect this standard to have a material effect on our financial statements. In March 2017, the FASB issued ASU No. 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” This update, effective for annual and interim reporting periods beginning January 1, 2018, will require segregation of these net benefit costs between operating and non-operating expenses. Currently, we report the net benefit costs associated with our defined benefit and postretirement plans in the “Compensation and benefits” line item of the Consolidated Statements of Income, as disclosed in Note 11, “Pensions and Other Postretirement Benefits.” When the ASU is implemented, only the service cost component of defined benefit pension cost and postretirement benefit cost will be reported within compensation costs, while all other components of net benefit cost will be presented within the “Other income – net” line item on the Consolidated Statements of Income. The standard requires retrospective application, and as such the adoption of this standard will result in offsetting increases in “Compensation and benefits” expense and “Other income – net” on the Consolidated Statements of Income for all periods of 2017 and 2016, with no impact on net income. We did not adopt the standard early.

Other Income - Net (Tables)

Other Income - Net (Tables)	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Other Income - Net	2017 2016 2015 ($ in millions) Rental income $ 87 $ 93 $ 80 Corporate-owned life insurance – net 33 20 (1 ) Royalties from coal 19 10 19 Interest income 13 10 8 Gains from sale of properties (including joint venture sales) 13 9 55 External advisor costs — (20 ) (8 ) Nonoperating depletion and depreciation (4 ) (4 ) (5 ) Taxes on nonoperating property (11 ) (11 ) (10 ) Charitable contributions (15 ) (9 ) (9 ) Other interest expense – net (including debt exchange fees) (17 ) (6 ) (4 ) Other (26 ) (21 ) (22 ) Total $ 92 $ 71 $ 103

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provisions For Income Taxes	2017 2016 2015 ($ in millions) Current: Federal $ 500 $ 612 $ 505 State 83 75 61 Total current taxes 583 687 566 Deferred: Federal (2,924 ) 206 292 State 65 21 28 Total deferred taxes (2,859 ) 227 320 Income taxes $ (2,276 ) $ 914 $ 886
Reconciliation Of Statutory Rate To Effective Rate	“Income taxes” in the Consolidated Statements of Income differs from the amounts computed by applying the statutory federal corporate tax rate as follows: 2017 2016 2015 Amount % Amount % Amount % ($ in millions) Federal income tax at statutory rate $ 1,095 35.0 $ 904 35.0 $ 855 35.0 State income taxes, net of federal tax effect 88 2.8 70 2.8 72 3.0 Excess tax benefits on stock-based compensation (39 ) (1.2 ) (17 ) (0.7 ) — — Equity in earnings related to tax reform (38 ) (1.2 ) — — — — Other, net (51 ) (1.7 ) (43 ) (1.7 ) (41 ) (1.7 ) Tax reform (3,331 ) (106.5 ) — — — — Income taxes $ (2,276 ) (72.8 ) $ 914 35.4 $ 886 36.3
Schedule Of Deferred Tax Assets And Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows: December 31, 2017 2016 ($ in millions) Deferred tax assets: Compensation and benefits, including postretirement benefits $ 235 $ 464 Accruals, including casualty and other claims 64 102 Other 67 62 Total gross deferred tax assets 366 628 Less valuation allowance (44 ) (39 ) Net deferred tax assets 322 589 Deferred tax liabilities: Property (6,212 ) (9,301 ) Other (434 ) (428 ) Total deferred tax liabilities (6,646 ) (9,729 ) Deferred income taxes $ (6,324 ) $ (9,140 )
Reconciliation Of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: December 31, 2017 2016 ($ in millions) Balance at beginning of year $ 27 $ 25 Additions based on tax positions related to the current year 4 3 Additions for tax positions of prior years 2 — Reductions for tax positions of prior years (2 ) — Settlements with taxing authorities (11 ) — Lapse of statutes of limitations (3 ) (1 ) Balance at end of year $ 17 $ 27

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule Of Carrying Amounts And Estimated Fair Values	The carrying amounts and estimated fair values for the remaining financial instruments, excluding investments accounted for under the equity method, consisted of the following at December 31: 2017 2016 Carrying Amount Fair Value Carrying Amount Fair Value ($ in millions) Long-term investments $ 26 $ 49 $ 116 $ 141 Long-term debt, including current maturities (9,736 ) (11,771 ) (10,112 ) (11,626 )
Schedule Of Fair Value Of Long-term Assets And Liabilities	The following tables set forth the fair value of long-term investment and long-term debt balances disclosed above by valuation technique level, within the fair value hierarchy (there were no level 3 valued assets or liabilities). Level 1 Level 2 Total ($ in millions) December 31, 2017 Long-term investments $ 4 $ 45 $ 49 Long-term debt, including current maturities (11,676 ) (95 ) (11,771 ) December 31, 2016 Long-term investments $ 4 $ 137 $ 141 Long-term debt, including current maturities (11,427 ) (199 ) (11,626 )

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Investments [Abstract]
Investments	December 31, 2017 2016 ($ in millions) Long-term investments: Equity method investments: Conrail Inc. $ 1,293 $ 1,199 TTX Company 629 471 Meridian Speedway LLC 272 274 Pan Am Southern LLC 154 155 Other 77 77 Total equity method investments 2,425 2,176 Corporate-owned life insurance at net cash surrender value 530 485 Other investments 26 116 Total long-term investments $ 2,981 $ 2,777

Properties (Tables)

Properties (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Properties	Accumulated Net Book Depreciation December 31, 2017 Cost Depreciation Value Rate (1) ($ in millions) Land $ 2,342 $ — $ 2,342 — Roadway: Rail and other track material 6,730 (1,961 ) 4,769 2.28 % Ties 5,181 (1,374 ) 3,807 3.37 % Ballast 2,654 (624 ) 2,030 2.71 % Construction in process 447 — 447 — Other roadway 13,636 (3,523 ) 10,113 2.59 % Total roadway 28,648 (7,482 ) 21,166 Equipment: Locomotives 5,658 (2,158 ) 3,500 3.77 % Freight cars 3,256 (1,286 ) 1,970 2.48 % Computers and software 610 (334 ) 276 10.61 % Construction in process 247 — 247 — Other equipment 1,004 (366 ) 638 5.06 % Total equipment 10,775 (4,144 ) 6,631 Other property 474 (283 ) 191 0.77 % Total properties $ 42,239 $ (11,909 ) $ 30,330 Accumulated Net Book Depreciation December 31, 2016 Cost Depreciation Value Rate (1) ($ in millions) Land $ 2,330 $ — $ 2,330 — Roadway: Rail and other track material 6,632 (1,997 ) 4,635 2.46 % Ties 5,011 (1,314 ) 3,697 3.25 % Ballast 2,559 (584 ) 1,975 2.64 % Construction in process 664 — 664 — Other roadway 13,096 (3,361 ) 9,735 2.51 % Total roadway 27,962 (7,256 ) 20,706 Equipment: Locomotives 5,525 (2,199 ) 3,326 3.65 % Freight cars 3,377 (1,345 ) 2,032 2.51 % Computers and software 552 (329 ) 223 10.40 % Construction in process 295 — 295 — Other equipment 972 (329 ) 643 4.71 % Total equipment 10,721 (4,202 ) 6,519 Other property 475 (279 ) 196 0.83 % Total properties $ 41,488 $ (11,737 ) $ 29,751 (1) Composite annual depreciation rate for the underlying assets, excluding the effects of the amortization of any deficiency (or excess) that resulted from our depreciation studies.

Current Liabilities (Tables)

Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Current Liabilities	December 31, 2017 2016 ($ in millions) Accounts payable: Accounts and wages payable $ 822 $ 650 Casualty and other claims (Note 16) 187 192 Due to Conrail (Note 5) 146 129 Vacation liability 133 134 Other 113 110 Total $ 1,401 $ 1,215 Other current liabilities: Interest payable $ 115 $ 119 Pension benefit obligations (Note 11) 17 16 Other 101 94 Total $ 233 $ 229

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt With Interest Rates And Maturities	Debt with weighted average interest rates and maturities is presented below: December 31, 2017 2016 ($ in millions) Notes and debentures: 5.32% maturing to 2022 $ 2,682 $ 3,232 4.42% maturing 2023 to 2031 2,965 2,746 4.54% maturing 2037 to 2052 4,404 3,190 6.81% maturing 2097 to 2111 531 1,328 Securitization borrowings and capital leases 102 202 Discounts, premiums, and debt issuance costs (848 ) (486 ) Total debt 9,836 10,212 Less current maturities and short-term debt (700 ) (650 ) Long-term debt excluding current maturities and short-term debt $ 9,136 $ 9,562 Long-term debt maturities subsequent to 2018 are as follows: 2019 $ 585 2020 314 2021 584 2022 600 2023 and subsequent years 7,053 Total $ 9,136

Lease Commitments (Tables)

Lease Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Future Minimum Lease Payments	Future minimum lease payments and operating lease expense are as follows: Future Minimum Lease Payments Operating Leases ($ in millions) 2018 $ 69 2019 66 2020 60 2021 55 2022 51 2023 and subsequent years 359 Total $ 660
Operating Lease Expense	Operating Lease Expense 2017 2016 2015 ($ in millions) Minimum rents $ 90 $ 98 $ 111 Contingent rents 79 73 84 Total $ 169 $ 171 $ 195

Other Liabilities (Tables)

Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Other Liabilities	December 31, 2017 2016 ($ in millions) Net other postretirement benefit obligations (Note 11) $ 309 $ 346 Net pension benefit obligations (Note 11) 296 333 Long-term advances from Conrail (Note 5) 280 280 Casualty and other claims (Note 16) 179 178 Deferred compensation 113 112 Other 170 193 Total $ 1,347 $ 1,442

Pensions And Other Postretire37

Pensions And Other Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pension And Other Postretirement Benefit Obligations And Plan Assets	Pension and Other Postretirement Benefit Obligations and Plan Assets Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 ($ in millions) Change in benefit obligations: Benefit obligation at beginning of year $ 2,420 $ 2,372 $ 528 $ 536 Service cost 38 36 7 7 Interest cost 80 82 15 16 Actuarial losses 143 66 6 14 Benefits paid (140 ) (136 ) (46 ) (45 ) Benefit obligation at end of year 2,541 2,420 510 528 Change in plan assets: Fair value of plan assets at beginning of year 2,073 2,040 182 189 Actual return on plan assets 423 152 40 17 Employer contribution 1 17 17 25 21 Benefits paid (140 ) (136 ) (46 ) (45 ) Fair value of plan assets at end of year 2,373 2,073 201 182 Funded status at end of year $ (168 ) $ (347 ) $ (309 ) $ (346 ) Amounts recognized in the Consolidated Balance Sheets: Noncurrent assets $ 145 $ 2 $ — $ — Current liabilities (17 ) (16 ) — — Noncurrent liabilities (296 ) (333 ) (309 ) (346 ) Net amount recognized $ (168 ) $ (347 ) $ (309 ) $ (346 ) Amounts included in accumulated other comprehensive loss (before tax): Net loss $ 781 $ 940 $ 11 $ 30 Prior service cost (benefit) 2 3 (283 ) (307 ) 1 Norfolk Southern is eligible to receive reimbursement from the Norfolk Southern Corporation Post-Retirement Benefits Trust (Trust), and the Trust had an outstanding liability to Norfolk Southern of $1 million at December 31, 2017 and $13 million at December 31, 2016 .
Pension And Other Postretirement Benefit Cost Components	Pension and Other Postretirement Benefit Cost Components 2017 2016 2015 ($ in millions) Pension benefits: Service cost $ 38 $ 36 $ 41 Interest cost 80 82 93 Expected return on plan assets (172 ) (173 ) (165 ) Amortization of net losses 51 51 65 Amortization of prior service cost 1 — — Net cost (benefit) $ (2 ) $ (4 ) $ 34 Other postretirement benefits: Service cost $ 7 $ 7 $ 7 Interest cost 15 16 21 Expected return on plan assets (15 ) (17 ) (19 ) Amortization of prior service benefit (24 ) (24 ) (24 ) Net benefit $ (17 ) $ (18 ) $ (15 )
Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Loss	Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income 2017 Pension Other ($ in millions) Net gain arising during the year $ (108 ) $ (19 ) Amortization of net losses (51 ) — Amortization of prior service benefit (cost) (1 ) 24 Total recognized in other comprehensive income $ (160 ) $ 5 Total recognized in net periodic cost and other comprehensive income $ (162 ) $ (12 )
Pension And Other Postretirement Benefit Assumptions	A summary of the major assumptions follows: 2017 2016 2015 Pension funded status: Discount rate 3.74 % 4.05 % 4.30 % Future salary increases 4.21 % 4.21 % 4.50 % Other postretirement benefits funded status: Discount rate 3.57 % 3.83 % 4.02 % Pension cost: Discount rate - service cost 4.31 % 4.64 % 3.95 % Discount rate - interest cost 3.43 % 3.51 % 3.95 % Return on assets in plans 8.25 % 8.25 % 8.25 % Future salary increases 4.21 % 4.50 % 4.50 % Other postretirement benefits cost: Discount rate - service cost 4.17 % 4.36 % 3.70 % Discount rate - interest cost 3.14 % 3.15 % 3.70 % Return on assets in plans 8.00 % 8.00 % 8.00 % Health care trend rate 6.56 % 6.30 % 6.56 %
Health Care Cost Trend Assumptions	To illustrate, a one-percentage point change in the assumed health care cost trend would have the following effects: One-percentage point Increase Decrease ($ in millions) Increase (decrease) in: Total service and interest cost components $ 1 $ (1 ) Postretirement benefit obligation 10 (9 )
Pension Plan Weighted-Average Asset Allocations, By Asset Category	Our pension plans’ weighted average asset allocations, by asset category, were as follows: Percentage of plan assets at December 31, 2017 2016 Domestic equity securities 49 % 51 % International equity securities 25 % 24 % Debt securities 24 % 23 % Cash and cash equivalents 2 % 2 % Total 100 % 100 %
Fair Value Of Plan Assets	The following table sets forth the pension plans’ assets by valuation technique level, within the fair value hierarchy (there were no level 3 valued assets). December 31, 2017 Level 1 Level 2 Total ($ in millions) Common stock $ 1,154 $ — $ 1,154 Common collective trusts: Debt securities — 562 562 International equity securities — 397 397 Commingled funds — 233 233 Interest bearing cash 23 — 23 U.S. government and agencies securities — 4 4 Total investments $ 1,177 $ 1,196 $ 2,373 December 31, 2016 Level 1 Level 2 Total ($ in millions) Common stock $ 1,142 $ — $ 1,142 Common collective trusts: Debt securities — 481 481 International equity securities — 324 324 Commingled funds — 79 79 Interest bearing cash 43 — 43 U.S. government and agencies securities — 4 4 Total investments $ 1,185 $ 888 $ 2,073
Estimated Future Benefit Payments	Benefit payments, which reflect expected future service, as appropriate, are expected to be paid as follows: Pension Benefits Other Postretirement Benefits ($ in millions) 2018 $ 143 $ 42 2019 143 41 2020 143 40 2021 144 38 2022 145 37 Years 2023 – 2027 731 169

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Options Granted Under LTIP and TSOP	The Committee granted stock options, RSUs and PSUs pursuant to the LTIP and granted stock options pursuant to the TSOP for the last three years as follows: 2017 2016 2015 Granted Weighted Average Grant-Date Fair Value Granted Weighted Average Grant-Date Fair Value Granted Weighted Average Grant-Date Fair Value Stock options: LTIP 341,120 $ 37.73 694,290 $ 19.92 643,890 $ 30.35 TSOP 144,440 31.33 302,320 14.75 181,320 24.71 Total 485,560 996,610 825,210 Restricted stock units 83,330 120.16 136,250 70.44 101,470 104.23 Performance share units 300,334 88.56 1,042,628 52.75 413,770 71.66
Schedule of Compensation Costs and Tax Benefits	Related compensation costs and tax benefits during the year were: 2017 2016 2015 ($ in millions) Stock-based compensation expense $ 45 $ 42 $ 42 Total tax benefit 54 31 13
Schedule Of Assumptions Used For LTIP And TSOP Grants	The assumptions for the LTIP and TSOP grants for the last three years are shown in the following table: 2017 2016 2015 Average expected volatility 26 % 27 % 25 % Average risk-free interest rate 2.51 % 2.00 % 1.83 % Average expected option term LTIP 8.6 years 8.9 years 9.3 years Average expected option term TSOP 8.3 years 8.6 years 9.1 years
Schedule Of Stock Option Activity	A summary of changes in stock options is presented below: Stock Options Weighted Avg. Exercise Price Outstanding at December 31, 2016 5,554,054 $ 72.57 Granted 485,560 120.25 Exercised (1,789,939 ) 60.28 Forfeited (15,608 ) 90.05 Outstanding at December 31, 2017 4,234,067 83.17
Summary Of Stock Options Exercised	The following table provides information related to options exercised for the last three years: 2017 2016 2015 ($ in millions) Options exercised 1,789,939 1,466,721 589,081 Total intrinsic value $ 114 $ 60 $ 27 Cash received upon exercise 104 74 29 Related tax benefits realized 35 13 7
Schedule Of Other Share Activity	2017 2016 2015 ($ in millions) RSUs vested 137,200 175,500 166,750 Common Stock issued net of tax witholding 81,318 103,936 99,337 Related tax benefit realized $ 3 $ 1 $ 4 2017 2016 2015 ($ in millions) PSUs earned 171,080 406,038 236,601 Common Stock issued net of tax witholding 99,805 241,757 141,386 Related tax benefit realized $ 1 $ 3 $ 3
Schedule Of Stock Available For Future Grants	Shares of Common Stock available for future grants and issued in connection with all features of the LTIP and the TSOP at December 31, were as follows: 2017 2016 2015 Available for future grants: LTIP 8,774,768 9,385,674 11,769,796 TSOP 410,895 544,217 832,676 Issued: LTIP 1,679,547 1,511,645 708,059 TSOP 291,515 300,769 121,745
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Other Share Activity	A summary of changes in RSUs is presented below: RSUs Weighted- Average Grant-Date Fair Value Nonvested at December 31, 2016 645,645 $ 80.68 Granted 83,330 120.16 Vested (137,200 ) 75.14 Forfeited (3,370 ) 108.47 Nonvested at December 31, 2017 588,405 87.40
Performance Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Other Share Activity	A summary of changes in PSUs is presented below: PSUs Weighted- Average Grant-Date Fair Value Balance at December 31, 2016 1,849,008 $ 61.17 Granted 300,334 88.56 Earned (171,080 ) 68.67 Unearned (226,780 ) 74.93 Forfeited (2,730 ) 58.09 Balance at December 31, 2017 1,748,752 63.36

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Loss	The components of “Other comprehensive income (loss)” reported in the Consolidated Statements of Comprehensive Income and changes in the cumulative balances of “Accumulated other comprehensive loss” reported in the Consolidated Balance Sheets consisted of the following: Balance at Beginning of Year Net Income (Loss) Reclassification Adjustments Balance at End of Year ($ in millions) Year ended December 31, 2017 Pensions and other postretirement liabilities $ (414 ) $ 95 $ 19 $ (300 ) Other comprehensive income of equity investees (73 ) 17 — (56 ) Accumulated other comprehensive loss $ (487 ) $ 112 $ 19 $ (356 ) Year ended December 31, 2016 Pensions and other postretirement liabilities $ (367 ) $ (64 ) $ 17 $ (414 ) Other comprehensive income of equity investees (78 ) 5 — (73 ) Accumulated other comprehensive loss $ (445 ) $ (59 ) $ 17 $ (487 )
Other Comprehensive Income (Loss) Of Equity Investees	“Other comprehensive income (loss)” reported in the Consolidated Statements of Comprehensive Income consisted of the following: Pretax Amount Tax (Expense) Benefit Net-of-Tax Amount ($ in millions) Year ended December 31, 2017 Net gain (loss) arising during the year: Pensions and other postretirement benefits $ 127 $ (32 ) $ 95 Reclassification adjustments for costs included in net income 28 (9 ) 19 Subtotal 155 (41 ) 114 Other comprehensive income of equity investees 19 (2 ) 17 Other comprehensive income $ 174 $ (43 ) $ 131 Year ended December 31, 2016 Net gain (loss) arising during the year: Pensions and other postretirement benefits $ (101 ) $ 37 $ (64 ) Reclassification adjustments for costs included in net income 27 (10 ) 17 Subtotal (74 ) 27 (47 ) Other comprehensive income of equity investees 5 — 5 Other comprehensive loss $ (69 ) $ 27 $ (42 ) Year ended December 31, 2015 Net gain (loss) arising during the year: Pensions and other postretirement benefits $ (117 ) $ 45 $ (72 ) Reclassification adjustments for costs included in net income 41 (16 ) 25 Other comprehensive loss $ (76 ) $ 29 $ (47 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share Calculation	The following table sets forth the calculation of basic and diluted earnings per share: Basic Diluted 2017 2016 2015 2017 2016 2015 ($ in millions except per share amounts, shares in millions) Net income $ 5,404 $ 1,668 $ 1,556 $ 5,404 $ 1,668 $ 1,556 Dividend equivalent payments (4 ) (5 ) (6 ) (2 ) (4 ) (5 ) Income available to common stockholders $ 5,400 $ 1,663 $ 1,550 $ 5,402 $ 1,664 $ 1,551 Weighted-average shares outstanding 287.9 293.9 301.9 287.9 293.9 301.9 Dilutive effect of outstanding options and share-settled awards 2.4 2.1 2.5 Adjusted weighted-average shares outstanding 290.3 296.0 304.4 Earnings per share $ 18.76 $ 5.66 $ 5.13 $ 18.61 $ 5.62 $ 5.10

Quarterly Financial Data (Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	Three Months Ended March 31 June 30 September 30 December 31 ($ in millions, except per share amounts) 2017 Railway operating revenues $ 2,575 $ 2,637 $ 2,670 $ 2,669 Income from railway operations 773 888 911 1,014 Net income 433 497 506 3,968 Earnings per share: Basic 1.49 1.72 1.76 13.91 Diluted 1.48 1.71 1.75 13.79 2016 Railway operating revenues $ 2,420 $ 2,454 $ 2,524 $ 2,490 Income from railway operations 723 770 820 761 Net income 387 405 460 416 Earnings per share: Basic 1.30 1.37 1.56 1.43 Diluted 1.29 1.36 1.55 1.42

Summary Of Significant Accoun42

Summary Of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)midepreciable_asset_class	Dec. 31, 2016USD ($)
Property, Plant and Equipment [Line Items]
Operating route miles | mi	19,500
Employees covered by collective bargaining agreements	80.00%
Allowance for doubtful accounts | $	$ 7	$ 4
Approximate number of depreciable asset classes used | depreciable_asset_class	75
Depreciation studies description	Our depreciation studies are conducted about every three years for equipment and every six years for track assets and other roadway property.
Equipment
Property, Plant and Equipment [Line Items]
Depreciation studies, period	3 years
Roadway
Property, Plant and Equipment [Line Items]
Depreciation studies, period	6 years
Intermodal
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	23.00%
Chemicals
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	16.00%
Agriculture/Consumer Products/Government
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	15.00%
Coal
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	17.00%
Metals/Construction
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	13.00%
Automotive
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	9.00%
Paper/Clay/Forest Products
Property, Plant and Equipment [Line Items]
Market groups percent of total railway operating revenues	7.00%

Summary Of Significant Accoun43

Summary Of Significant Accounting Polices (New Accounting Pronouncements) (Details) $ in Millions	Dec. 31, 2017USD ($)
Accounting Policies [Abstract]
Operating leases	$ 660

Other Income - Net (Details)

Other Income - Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Rental income	$ 87	$ 93	$ 80
Corporate-owned life insurance – net	33	20	(1)
Royalties from coal	19	10	19
Interest income	13	10	8
Gains from sale of properties (including joint venture sales)	13	9	55
External advisor costs	0	(20)	(8)
Nonoperating depletion and depreciation	(4)	(4)	(5)
Taxes on nonoperating property	(11)	(11)	(10)
Charitable contributions	(15)	(9)	(9)
Other interest expense – net (including debt exchange fees)	(17)	(6)	(4)
Other	(26)	(21)	(22)
Total	$ 92	$ 71	$ 103

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Tax Credit Carryforward [Line Items]
Change in valuation allowance	$ 5	$ 4
Unrecognized tax benefits that would impact effective tax rate	11
Refund adjustment from taxing authority	46
Purchased Services and Rent
Tax Credit Carryforward [Line Items]
Benefit in Purchased Services and Rents	151
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit	151
Income Taxes [Member]
Tax Credit Carryforward [Line Items]
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit	$ 3,331

Income Taxes (Provisions For In

Income Taxes (Provisions For Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 500	$ 612	$ 505
State	83	75	61
Total current taxes	583	687	566
Deferred:
Federal	(2,924)	206	292
State	65	21	28
Total deferred taxes	(2,859)	227	320
Income taxes	$ (2,276)	$ 914	$ 886

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Statutory Rate To Effective Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate	$ 1,095	$ 904	$ 855
State income taxes, net of federal tax effect	88	70	72
Excess tax benefits associated with stock-based compensation, net of federal tax effect	(39)	(17)	0
Equity in earnings related to tax reform	(38)	0	0
Other, net	(51)	(43)	(41)
Tax reform	(3,331)	0	0
Income taxes	$ (2,276)	$ 914	$ 886
Federal income tax at statutory rate, percentage of net income	35.00%	35.00%	35.00%
State income taxes, net of federal tax effect, percentage of net income	2.80%	2.80%	3.00%
Excess tax benefits associated with stock-based compensation, net of federal tax effect, percentage of net income	(1.20%)	(0.70%)	0.00%
State tax law changes, net of federal tax effect, percentage of net income	(1.20%)	0.00%	0.00%
Other, net, percentage of net income	(1.70%)	(1.70%)	(1.70%)
Tax reform	(106.50%)	0.00%	0.00%
Provision for income taxes, percentage of net income	(72.80%)	35.40%	36.30%

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Compensation and benefits, including postretirement benefits	$ 235	$ 464
Accruals, including casualty and other claims	64	102
Other	67	62
Total gross deferred tax assets	366	628
Less valuation allowance	(44)	(39)
Net deferred tax asset	322	589
Deferred tax liabilities:
Property	(6,212)	(9,301)
Other	(434)	(428)
Total deferred tax liabilities	(6,646)	(9,729)
Deferred income taxes	$ (6,324)	$ (9,140)

Income Taxes (Reconciliation 49

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 27	$ 25
Additions based on tax positions related to the current year	4	3
Additions for tax positions of prior years	2	0
Reductions for tax positions of prior years	(2)	0
Settlements with taxing authorities	(11)	0
Lapse of statutes of limitations	(3)	(1)
Balance at end of year	$ 17	$ 27

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Long-term investments, carrying value	$ 26	$ 116
Long-term investments, fair value	49	141
Long-term debt, including current maturities, carrying value	(9,736)	(10,112)
Long-term debt, including current maturities, fair value	$ (11,771)	$ (11,626)

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Fair Value of Long-term Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term investments, fair value	$ 49	$ 141
Long-term debt, including current maturities, fair value	(11,771)	(11,626)
Fair Value Inputs Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term investments, fair value	4	4
Long-term debt, including current maturities, fair value	(11,676)	(11,427)
Fair Value Inputs Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term investments, fair value	45	137
Long-term debt, including current maturities, fair value	$ (95)	$ (199)

Investments (Details)

Investments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Equity Method Investments	$ 2,425	$ 2,176
Corporate-owned life insurance at net cash surrender value	530	485
Other investments	26	116
Total long-term investments	2,981	2,777
Conrail Inc.
Schedule of Investments [Line Items]
Equity Method Investments	1,293	1,199
TTX Company
Schedule of Investments [Line Items]
Equity Method Investments	629	471
Meridian Speedway LLC
Schedule of Investments [Line Items]
Equity Method Investments	272	274
Pan Am Southern LLC
Schedule of Investments [Line Items]
Equity Method Investments	154	155
Other
Schedule of Investments [Line Items]
Equity Method Investments	$ 77	$ 77

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Deferred tax liabilities	$ 6,324	$ 9,140
Future minimum lease payments, 2022 and subsequent years	359
Shared Assets Areas CRC Lease
Schedule of Investments [Line Items]
Future annual minimum payments, due next five years	38
Future minimum lease payments, 2022 and subsequent years	$ 91
Conrail Equity
Schedule of Investments [Line Items]
Equity method investment, ownership percentage	58.00%
Conrail Voting
Schedule of Investments [Line Items]
Equity method investment, ownership percentage	50.00%
Conrail Inc.
Schedule of Investments [Line Items]
Pension plan status change in investment, affiliate	$ 19	5
Portion of pension plan change attributable to other comprehensive income (loss), affiliate	17	5
Deferred tax liabilities	2
Portion of pension plan change attributable to deferred taxes, affiliate		1
Difference between investment in Conrail and share of Conrail's underlying net equity	519
Expenses from transactions with related party	141	151	$ 154
General and administrative support to Conrail	8
Due to Conrail, current	146	129
Due to Conrail, noncurrent	$ 280	$ 280
Due to Conrail, noncurrent, maturity date	2,044	2,044
Due to Conrail, average interest rate	2.90%	2.90%
TTX Company
Schedule of Investments [Line Items]
Equity method investment, ownership percentage	19.65%
Expenses from transactions with related party	$ 237	$ 229	219
Purchased Services and Rent
Schedule of Investments [Line Items]
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit	151
Purchased Services and Rent | Conrail Inc.
Schedule of Investments [Line Items]
Equity in earnings of investee	75	47	42
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit	33
Purchased Services and Rent | TTX Company
Schedule of Investments [Line Items]
Equity in earnings of investee	158	$ 26	$ 21
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit	$ 115

Properties (Details)

Properties (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Cost		$ 42,239	$ 41,488
Accumulated Depreciation		(11,909)	(11,737)
Net Book Value		30,330	29,751
Land
Property, Plant and Equipment [Line Items]
Cost		2,342	2,330
Accumulated Depreciation		0	0
Net Book Value		$ 2,342	2,330
Depreciation Rate	[1]	0.00%
Rail and other track material
Property, Plant and Equipment [Line Items]
Cost		$ 6,730	6,632
Accumulated Depreciation		(1,961)	(1,997)
Net Book Value		$ 4,769	$ 4,635
Depreciation Rate	[1]	2.28%	2.46%
Ties
Property, Plant and Equipment [Line Items]
Cost		$ 5,181	$ 5,011
Accumulated Depreciation		(1,374)	(1,314)
Net Book Value		$ 3,807	$ 3,697
Depreciation Rate	[1]	3.37%	3.25%
Ballast
Property, Plant and Equipment [Line Items]
Cost		$ 2,654	$ 2,559
Accumulated Depreciation		(624)	(584)
Net Book Value		$ 2,030	$ 1,975
Depreciation Rate	[1]	2.71%	2.64%
Construction in process
Property, Plant and Equipment [Line Items]
Cost		$ 447	$ 664
Accumulated Depreciation		0	0
Net Book Value		$ 447	664
Depreciation Rate	[1]	0.00%
Other roadway
Property, Plant and Equipment [Line Items]
Cost		$ 13,636	13,096
Accumulated Depreciation		(3,523)	(3,361)
Net Book Value		$ 10,113	$ 9,735
Depreciation Rate	[1]	2.59%	2.51%
Total roadway
Property, Plant and Equipment [Line Items]
Cost		$ 28,648	$ 27,962
Accumulated Depreciation		(7,482)	(7,256)
Net Book Value		21,166	20,706
Locomotives
Property, Plant and Equipment [Line Items]
Cost		5,658	5,525
Accumulated Depreciation		(2,158)	(2,199)
Net Book Value		$ 3,500	$ 3,326
Depreciation Rate	[1]	3.77%	3.65%
Freight cars
Property, Plant and Equipment [Line Items]
Cost		$ 3,256	$ 3,377
Accumulated Depreciation		(1,286)	(1,345)
Net Book Value		$ 1,970	$ 2,032
Depreciation Rate	[1]	2.48%	2.51%
Computers and software
Property, Plant and Equipment [Line Items]
Cost		$ 610	$ 552
Accumulated Depreciation		(334)	(329)
Net Book Value		$ 276	$ 223
Depreciation Rate	[1]	10.61%	10.40%
Construction in process
Property, Plant and Equipment [Line Items]
Cost		$ 247	$ 295
Accumulated Depreciation		0	0
Net Book Value		$ 247	295
Depreciation Rate	[1]	0.00%
Other equipment
Property, Plant and Equipment [Line Items]
Cost		$ 1,004	972
Accumulated Depreciation		(366)	(329)
Net Book Value		$ 638	$ 643
Depreciation Rate	[1]	5.06%	4.71%
Total equipment
Property, Plant and Equipment [Line Items]
Cost		$ 10,775	$ 10,721
Accumulated Depreciation		(4,144)	(4,202)
Net Book Value		6,631	6,519
Other property
Property, Plant and Equipment [Line Items]
Cost		474	475
Accumulated Depreciation		(283)	(279)
Net Book Value		$ 191	$ 196
Depreciation Rate	[1]	0.77%	0.83%
[1]	Composite annual depreciation rate for the underlying assets, excluding the effects of the amortization of any deficiency (or excess) that resulted from our depreciation studies.

Properties (Narrative) (Details

Properties (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Costs Of obtaining rights to natural resources	$ 336	$ 336
Accumulated depreciation associated with costs of obtaining rights to natural resources	200	199
Interest costs incurred on debt	570	583	$ 566
Interest costs capitalized	$ 20	$ 20	$ 21

Current Liabilities (Details)

Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts and wages payable	$ 822	$ 650
Casualty and other claims (Note 16)	187	192
Vacation liability	133	134
Other	113	110
Total	1,401	1,215
Interest payable	115	119
Other	101	94
Total	233	229
Pension Plan
Pension benefit obligations (Note 11)	17	16
Conrail Inc [Member]
Due to Conrail (Note 5)	$ 146	$ 129

Debt (Debt With Interest Rates

Debt (Debt With Interest Rates And Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt	$ 9,836	$ 10,212
Discounts, premiums, and debt issuance costs	(848)	(486)
Less current maturities and short-term debt	(700)	(650)
Long-term debt	9,136	9,562
2,019	585
2,020	314
2,021	584
2,022	600
2023 and subsequent years	7,053
Short-term debt	100	100
5.32% maturing to 2022
Debt Instrument [Line Items]
Debt	$ 2,682	3,232
Long-term debt, weighted average interest rate	5.32%
4.42% maturing 2023 to 2031
Debt Instrument [Line Items]
Debt	$ 2,965	2,746
Long-term debt, weighted average interest rate	4.42%
4.54% maturing 2037 to 2052
Debt Instrument [Line Items]
Debt	$ 4,404	3,190
Long-term debt, weighted average interest rate	4.54%
6.81% maturing 2097 to 2111
Debt Instrument [Line Items]
Debt	$ 531	1,328
Long-term debt, weighted average interest rate	6.81%
Securitization Borrowings and Capital Leases
Debt Instrument [Line Items]
Debt	$ 102	$ 202

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Exchange of debt amount	$ 613,000,000	$ 551,000,000
Gain (loss) on exchange of debt	0	0
Long-term debt	9,736,000,000			$ 9,736,000,000	$ 10,112,000,000
Short-term debt	100,000,000			$ 100,000,000	100,000,000
Senior Notes
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt	$ 750,000,000	$ 750,000,000
Debt instrument, interest rate	3.942%	4.05%		3.942%
Payment for debt premium on exchange of debt	$ 52,000,000
Securitization Borrowings
Debt Instrument [Line Items]
Credit agreement	350,000,000			$ 350,000,000
Proceeds from short-term debt					100,000,000
Repayments of short-term debt				100,000,000	100,000,000
Accounts receivable securitization balance	$ 100,000,000			$ 100,000,000	$ 200,000,000
Average variable interest rate	3.21%			3.21%	2.47%
Long-term debt					$ 100,000,000
Short-term debt					100,000,000
Collateral for securitization borrowings	$ 751,000,000			$ 751,000,000	$ 704,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit agreement	$ 750,000,000			$ 750,000,000
Credit agreement term, years				5 years
6.00% Debt Maturing 2105
Debt Instrument [Line Items]
Debt instrument, interest rate	6.00%	6.00%		6.00%
Exchange of debt amount	$ 241,000,000	$ 125,000,000
4.80% Debt Maturing in 2043
Debt Instrument [Line Items]
Debt instrument, interest rate	4.80%			4.80%
Exchange of debt amount	$ 208,000,000
7.05% Debt Maturing in 2037
Debt Instrument [Line Items]
Debt instrument, interest rate	7.05%			7.05%
Exchange of debt amount	$ 78,000,000
7.80% Debt Maturing in 2027
Debt Instrument [Line Items]
Debt instrument, interest rate	7.80%			7.80%
Exchange of debt amount	$ 49,000,000
7.25% Debt Maturing in 2031
Debt Instrument [Line Items]
Debt instrument, interest rate	7.25%			7.25%
Exchange of debt amount	$ 32,000,000
6% Debt Maturing 2111
Debt Instrument [Line Items]
Debt instrument, interest rate	6.00%	6.00%		6.00%
Exchange of debt amount	$ 5,000,000	$ 378,000,000
7.9% Debt Maturing 2097
Debt Instrument [Line Items]
Debt instrument, interest rate		7.90%
Exchange of debt amount		$ 48,000,000
June 2016 Senior Note 2.90 Due 2026
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt			$ 300,000,000
Debt instrument, interest rate			3.15%

Lease Commitments (Details)

Lease Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
2018 - Operating Leases	$ 69
2019 - Operating Leases	66
2020 - Operating Leases	60
2021 - Operating Leases	55
2022 - Operating Leases	51
2023 and subsequent years	359
Total - Operating Leases	660
Operating lease expense - minimum rents	90	$ 98	$ 111
Operating lease expense - contingent rents	79	73	84
Total operating lease expense	$ 169	$ 171	$ 195

Other Liabilities (Details)

Other Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Casualty and other claims (Note 16)	$ 179	$ 178
Deferred compensation	113	112
Other	170	193
Total	1,347	1,442
Conrail Inc [Member]
Schedule of Investments [Line Items]
Long-term advances from Conrail (Note 5)	280	280
Other Postretirement Benefits Plan [Member]
Schedule of Investments [Line Items]
Defined benefit pension plan, liabilities, noncurrent	309	346
Pension Plan
Schedule of Investments [Line Items]
Defined benefit pension plan, liabilities, noncurrent	$ 296	$ 333

Pensions And Other Postretire61

Pensions And Other Postretirement Benefits (Pension And Other Postretirement Benefit Obligations And Plan Assets) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Postretirement benefits reimbursement receivable		$ 1	$ 13
Pension Plan
Change in benefit obligations:
Benefit obligation at beginning of year		2,420	2,372
Service cost		38	36	$ 41
Interest cost		80	82	93
Actuarial losses		143	66
Benefits paid		(140)	(136)
Benefit obligation at end of year		2,541	2,420	2,372
Change in plan assets:
Fair value of plan assets at beginning of year		2,073	2,040
Actual return on plan assets		423	152
Employer contribution	[1]	17	17
Benefits paid		(140)	(136)
Fair value of plan assets at end of year		2,373	2,073	2,040
Funded status at end of year		(168)	(347)
Noncurrent assets		145	2
Current liabilities		(17)	(16)
Noncurrent liabilities		(296)	(333)
Net amount recognized		(168)	(347)
Net loss		781	940
Prior service cost (benefit)		2	3
OPEB
Change in benefit obligations:
Benefit obligation at beginning of year		528	536
Service cost		7	7	7
Interest cost		15	16	21
Actuarial losses		6	14
Benefits paid		(46)	(45)
Benefit obligation at end of year		510	528	536
Change in plan assets:
Fair value of plan assets at beginning of year		182	189
Actual return on plan assets		40	17
Employer contribution	[1]	25	21
Benefits paid		(46)	(45)
Fair value of plan assets at end of year		201	182	$ 189
Funded status at end of year		(309)	(346)
Noncurrent assets		0	0
Current liabilities		0	0
Noncurrent liabilities		(309)	(346)
Net amount recognized		(309)	(346)
Net loss		11	30
Prior service cost (benefit)		$ (283)	$ (307)
[1]	Norfolk Southern is eligible to receive reimbursement from the Norfolk Southern Corporation Post-Retirement Benefits Trust (Trust), and the Trust had an outstanding liability to Norfolk Southern of $1 million at December 31, 2017 and $13 million at December 31, 2016.

Pensions And Other Postretire62

Pensions And Other Postretirement Benefits (Pension And Other Postretirement Benefit Cost Components) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 38	$ 36	$ 41
Interest cost	80	82	93
Expected return on plan assets	(172)	(173)	(165)
Amortization of net losses	51	51	65
Amortization of prior service cost	1	0	0
Net cost	(2)	(4)	34
OPEB
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	7	7
Interest cost	15	16	21
Expected return on plan assets	(15)	(17)	(19)
Amortization of net losses	0
Amortization of prior service cost	(24)	(24)	(24)
Net cost	$ (17)	$ (18)	$ (15)

Pensions And Other Postretire63

Pensions And Other Postretirement Benefits (Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Total recognized in other comprehensive income	$ 155	$ (74)	$ (76)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net gain arising during the year	(108)
Amortization of net losses	(51)	$ (51)	$ (65)
Amortization of prior service benefit (cost)	(1)
Total recognized in other comprehensive income	(160)
Total recognized in net periodic cost and other comprehensive income	(162)
OPEB
Defined Benefit Plan Disclosure [Line Items]
Net gain arising during the year	(19)
Amortization of net losses	0
Amortization of prior service benefit (cost)	24
Total recognized in other comprehensive income	5
Total recognized in net periodic cost and other comprehensive income	$ (12)

Pensions And Other Postretire64

Pensions And Other Postretirement Benefits (Pension And Other Postretirement Benefit Assumptions) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Return on assets in plans	8.25%
Funded Plan [Member] | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.74%	4.05%	4.30%
Future salary increases	4.21%	4.21%	4.50%
Funded Plan [Member] | OPEB
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.57%	3.83%	4.02%
Unfunded Plan [Member] | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Future salary increases	4.21%	4.50%	4.50%
Return on assets in plans	8.25%	8.25%	8.25%
Unfunded Plan [Member] | OPEB
Defined Benefit Plan Disclosure [Line Items]
Return on assets in plans	8.00%	8.00%	8.00%
Health care trend rate	6.56%	6.30%	6.56%
Unfunded Plan [Member] | Service cost [Member] | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.31%	4.64%	3.95%
Unfunded Plan [Member] | Service cost [Member] | OPEB
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.17%	4.36%	3.70%
Unfunded Plan [Member] | interest cost [Member] | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.43%	3.51%	3.95%
Unfunded Plan [Member] | interest cost [Member] | OPEB
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.14%	3.15%	3.70%

Pensions And Other Postretire65

Pensions And Other Postretirement Benefits (Health Care Cost Trend Assumptions) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Retirement Benefits [Abstract]
One-percentage point increase change in total service and interest cost components	$ 1
One-percentage point decrease change total service and interest cost components	(1)
One-percentage point increase change in postretirement benefit obligations	10
One-percentage point decrease change in postretirement benefit obligations	$ (9)

Pensions And Other Postretire66

Pensions And Other Postretirement Benefits (Pension Plan Weighted-Average Asset Allocations, By Asset Category) (Details)	Dec. 31, 2017	Dec. 31, 2016
Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	100.00%	100.00%
Equity Securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	25.00%	24.00%
Equity Securities | Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	49.00%	51.00%
Debt Securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	39.00%	33.00%
Debt Securities | Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	24.00%	23.00%
Cash and Cash Equivalents | Pension Plan
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual plan asset allocations	2.00%	2.00%

Pensions And Other Postretire67

Pensions And Other Postretirement Benefits (Fair Value Of Plan Assets) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 2,373	$ 2,073
Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,177	1,185
Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,196	888
Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,154	1,142
Common Stock | Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,154	1,142
Common Stock | Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	562	481
Debt Securities | Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt Securities | Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	562	481
International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	397	324
International equity securities | Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International equity securities | Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	397	324
Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	233	79
Commingled Funds | Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Commingled Funds | Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	233	79
Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23	43
Interest bearing cash | Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23	43
Interest bearing cash | Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. government and agencies securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	4
U.S. government and agencies securities | Fair Value Inputs Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. government and agencies securities | Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4	$ 4

Pensions And Other Postretire68

Pensions And Other Postretirement Benefits (Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2017USD ($)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 143
2,019	143
2,020	143
2,021	144
2,022	145
Years 2023 – 2027	731
OPEB
Defined Benefit Plan Disclosure [Line Items]
2,018	42
2,019	41
2,020	40
2,021	38
2,022	37
Years 2023 – 2027	$ 169

Pensions And Other Postretire69

Pensions And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan's accumulated benefit obligation	$ 2,300	$ 2,200
Unfunded pension plans projected benefit obligation	313	286
Unfunded pension plans accumulated benefit obligations	267	252
Multiemployer plan, contributions by employer	44	37	$ 32
Defined contribution plan, cost	23	$ 21	$ 21
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Estimated net loss for defined pension plans amortized from AOCI into net periodic cost	$ 57
Assumed increases in per capita cost of covered health care benefits	6.30%
Ultimate health care cost trend rate	5.00%
Pension plan assets target allocation for equity	75.00%
Actual plan asset allocations	100.00%	100.00%
Assumed rate of return on pension plan assets	8.25%
Expected contribution for the next fiscal year	$ 17
OPEB
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, future amortization of prior service cost (Credit)	24
Expected contribution for the next fiscal year	43
Fair Value Inputs Level 2
Defined Benefit Plan Disclosure [Line Items]
Trust-owned life insurance fair value	$ 201	$ 182
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocations	25.00%	24.00%
Equity Securities | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocations	49.00%	51.00%
Equity Securities | OPEB
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocations	61.00%	67.00%
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocations	39.00%	33.00%
Debt Securities | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocations	24.00%	23.00%
Cash and Cash Equivalents | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocations	2.00%	2.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage	0.5
Maximum
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage	0.75

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future grants (in shares)	8,774,768
Amended LTIP plan-award granted as an option or stock appreciation right (in shares)	1
Amended LTIP plan - award granted in a form other than option or stock appreciation right (in shares)	1.61
Dividend yield for period dividend equivalents paid		0.00%	0.00%
Aggregate intrinsic value of options outstanding	$ 261
Weighted average remaining contractual term of options outstanding	6 years 2 months 12 days
Number of shares exercisable (in shares)	2,221,577
Aggregate intrinsic value of options exercisable	$ 157
Exercisable weighted average exercise price (in dollars per share)	$ 74.06
Weighted average remaining contractual term of options exercisable	4 years 9 months 18 days
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for grant (in shares)	104,125,000
Available for future grants (in shares)	8,774,768	9,385,674	11,769,796
LTIP dividend equivalent payment, in years	4 years
Dividend yield for period dividend equivalents paid	0.00%
Vesting period	4 years	4 years	4 years
TSOP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for grant (in shares)	6,000,000
Available for future grants (in shares)	410,895	544,217	832,676
Vesting period	3 years	3 years	3 years
LTIP And TSOP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield for period dividend equivalents paid	2.04%	3.37%	2.27%
Unrecognized compensation related to stock options granted	$ 10
Unrecognized compensation, weighted average period of recognition	2 years 2 months 12 days
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation related to stock options granted	$ 8
Unrecognized compensation, weighted average period of recognition	3 years 2 months 12 days
Vesting period	5 years	5 years	5 years
Performance Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation related to stock options granted	$ 6
Unrecognized compensation, weighted average period of recognition	1 year 9 months 18 days

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule of Options Granted Under LTIP and TSOP) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	485,560	996,610	825,210
Weighted average exercise price of stock options granted (in dollars per share)	$ 120.25
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	341,120	694,290	643,890
Weighted average exercise price of stock options granted (in dollars per share)	$ 37.73	$ 19.92	$ 30.35
TSOP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	144,440	302,320	181,320
Weighted average exercise price of stock options granted (in dollars per share)	$ 31.33	$ 14.75	$ 24.71
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	83,330	136,250	101,470
Weighted average exercise price of stock options granted (in dollars per share)	$ 120.16	$ 70.44	$ 104.23
Performance Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	300,334	1,042,628	413,770
Weighted average exercise price of stock options granted (in dollars per share)	$ 88.56	$ 52.75	$ 71.66

Stock-Based Compensation (Sch72

Stock-Based Compensation (Schedule of Compensation Costs and Tax Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	$ 45	$ 42	$ 42
Total tax benefit	$ 54	$ 31	$ 13

Stock-Based Compensation (Sch73

Stock-Based Compensation (Schedule Of Assumptions Used For LTIP And TSOP Grants) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average expected volatility rate	26.00%	27.00%	25.00%
Average risk-free interest rate	2.51%	2.00%	1.83%
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average expected option term, in years	8 years 7 months 6 days	8 years 10 months 24 days	9 years 3 months 18 days
TSOP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average expected option term, in years	8 years 3 months 18 days	8 years 7 months 6 days	9 years 1 month 6 days

Stock-Based Compensation (Sch74

Stock-Based Compensation (Schedule Of Options) (Details) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Related tax benefit realized	$ 54	$ 31	$ 13
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested (in shares)	171,080	406,038	236,601
Common stock, shares, issued (in shares)	99,805	241,757	141,386
Related tax benefit realized	$ 1	$ 3	$ 3
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested (in shares)	137,200	175,500	166,750
Common stock, shares, issued (in shares)	81,318	103,936	99,337
Related tax benefit realized	$ 3	$ 1	$ 4

Stock-Based Compensation (Sch75

Stock-Based Compensation (Schedule Of Stock Option Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at December 31, 2016 (in shares)	5,554,054
Granted (in shares)	485,560	996,610	825,210
Exercised (in shares)	(1,789,939)	(1,466,721)	(589,081)
Forfeited (in shares)	(15,608)
Outstanding at December 31, 2017 (in shares)	4,234,067	5,554,054
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price of stock options outstanding at December 31, 2016 (in dollars per share)	$ 72.57
Weighted average exercise price of stock options granted (in dollars per share)	120.25
Weighted average exercise price of stock options exercised (in dollars per share)	60.28
Weighted average exercise price of stock options forfeited (in dollars per share)	90.05
Weighted average exercise price of stock options outstanding at December 31, 2017 (in dollars per share)	$ 83.17	$ 72.57

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of Stock Options Exercised) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options exercised (in shares)	1,789,939	1,466,721	589,081
Total intrinsic value	$ 114	$ 60	$ 27
Cash received upon exercise	104	74	29
Related tax benefits realized	$ 35	$ 13	$ 7

Stock-Based Compensation (Sum77

Stock-Based Compensation (Summary Of Stock Awards Outstanding) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Balance at December 31, 2016 (in shares)	645,645
Granted (in shares)	83,330
Vested (in shares)	(137,200)	(175,500)	(166,750)
Forfeited (in shares)	(3,370)
Balance at December 31, 2017 (in shares)	588,405	645,645
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant-date fair value at December 31, 2016 (in dollars per share)	$ 80.68
Weighted-average grant-date fair value of shares granted (in dollars per share)	120.16
Weighted-average grant-date fair value of shares vested (in dollars per share)	75.14
Weighted-average grant-date fair value of shares forfeited (in dollars per share)	108.47
Weighted-average grant-date fair value at December 31, 2017 (in dollars per share)	$ 87.40	$ 80.68
Performance Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Balance at December 31, 2016 (in shares)	1,849,008
Granted (in shares)	300,334
Vested (in shares)	(171,080)	(406,038)	(236,601)
Unearned (in shares)	(226,780)
Forfeited (in shares)	(2,730)
Balance at December 31, 2017 (in shares)	1,748,752	1,849,008
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant-date fair value at December 31, 2016 (in dollars per share)	$ 61.17
Weighted-average grant-date fair value of shares granted (in dollars per share)	88.56
Weighted-average grant-date fair value of shares earned - paid in Common Stock (in dollars per share)	68.67
Weighted-average grant-date fair value of shares unearned (in dollars per share)	74.93
Weighted-average grant-date fair value of shares forfeited (in dollars per share)	58.09
Weighted-average grant-date fair value at December 31, 2017 (in dollars per share)	$ 63.36	$ 61.17

Stock-Based Compensation (Sch78

Stock-Based Compensation (Schedule Of Stock Available For Future Grants) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future grants (in shares)	8,774,768
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future grants (in shares)	8,774,768	9,385,674	11,769,796
Common stock, shares, issued (in shares)	1,679,547	1,511,645	708,059
TSOP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future grants (in shares)	410,895	544,217	832,676
Common stock, shares, issued (in shares)	291,515	300,769	121,745

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Treasury stock, number of shares held	20,320,777	20,320,777
Treasury stock, value	$ 19	$ 19

Stockholders' Equity - Accumula

Stockholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning of period	$ (487)	$ (445)
Other comprehensive income (loss), before reclassifications, net of tax	112	(59)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	19	17
Accumulated other comprehensive loss, end of period	(356)	(487)	$ (445)
Pensions And Other Postretirement Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Pensions and other postretirement liabilities, beginning of year	(414)	(367)
Other comprehensive income (loss), before reclassifications, net of tax	95	(64)	(72)
Pensions and other postretirement liabilities, reclassification adjustments	19	17	25
Pensions and other postretirement liabilities, end of year	(300)	(414)	(367)
Accumulated Other Comprehensive Loss Equity Investees
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning of period	(73)	(78)
Other comprehensive income (loss), before reclassifications, net of tax	17	5
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Accumulated other comprehensive loss, end of period	$ (56)	$ (73)	$ (78)

Stockholders' Equity - Other Co

Stockholders' Equity - Other Comprehensive Income (Loss) Of Equity Investees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, net of tax	$ 112	$ (59)
Total recognized in other comprehensive income	155	(74)	$ (76)
Other comprehensive income (loss), before tax	174	(69)	(76)
Other comprehensive income (loss), tax	(43)	27	29
Other comprehensive income (loss), net of tax	131	(42)	(47)
Pensions And Other Postretirement Liabilities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, before tax	127	(101)	(117)
Other comprehensive income (loss) before reclassifications, tax	(32)	37	45
Other comprehensive income (loss), before reclassifications, net of tax	95	(64)	(72)
Reclassification from accumulated other comprehensive income, before tax	28	27	41
Reclassification from AOCI, tax	(9)	(10)	(16)
Pensions and other postretirement liabilities, reclassification adjustments	19	17	25
Total recognized in other comprehensive income	155
Other comprehensive (income) loss, pension and other postretirement benefit plans, tax	(41)
Other comprehensive (income) loss, pension and other postretirement benefit plans, adjustment, net of tax	114
Accumulated Other Comprehensive Loss Equity Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, net of tax	17	5
Other comprehensive income (loss), before tax	19	5	$ 0
Other comprehensive income (loss), tax	(2)
Other comprehensive income (loss), net of tax	$ 17
Pretax Amount
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Pension And Other Postretirement Other Comprehensive Income Loss		(74)
Other Comprehensive Income Loss Of Equity Investees		5
Tax Expense Benefit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Pension And Other Postretirement Other Comprehensive Income Loss		27
Other Comprehensive Income Loss Of Equity Investees		0
Net Of Tax Amount
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Pension And Other Postretirement Other Comprehensive Income Loss		(47)
Other Comprehensive Income Loss Of Equity Investees		$ 5

Stock Repurchase Program (Detai

Stock Repurchase Program (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 26, 2017
Stock Repurchase Program [Abstract]
Stock repurchased and retired during period (in shares)	8,200,000	9,200,000	11,300,000
Stock repurchased and retired during period, cost	$ 1,012	$ 803	$ 1,075
New stock repurchase program (in shares)				50,000,000
Remaining number of shares authorized to be repurchased (in shares)	56,500,000
Stock repurchased and retired since beginning of stock repurchase program in 2006 (in shares)	168,500,000
Stock repurchased and retired since beginning of stock repurchase program in 2006, cost	$ 11,300

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 3,968	$ 506	$ 497	$ 433	$ 416	$ 460	$ 405	$ 387	$ 5,404	$ 1,668	$ 1,556
Dividend equivalent payments, Basic									(4)	(5)	(6)
Dividend equivalent payments, Diluted									(2)	(4)	(5)
Income available to common stockholder's, Basic									5,400	1,663	1,550
Income available to common stockholder's, Diluted									$ 5,402	$ 1,664	$ 1,551
Weighted-average shares outstanding, basic (in shares)									287.9	293.9	301.9
Dilutive effect of outstanding options and share-settled awards (in shares)									2.4	2.1	2.5
Adjusted weighted-average shares outstanding, diluted (in shares)									290.3	296	304.4
Basic (in dollars per share)	$ 13.91	$ 1.76	$ 1.72	$ 1.49	$ 1.43	$ 1.56	$ 1.37	$ 1.30	$ 18.76	$ 5.66	$ 5.13
Diluted (in dollars per share)	$ 13.79	$ 1.75	$ 1.71	$ 1.48	$ 1.42	$ 1.55	$ 1.36	$ 1.29	$ 18.61	$ 5.62	$ 5.10

Earnings Per Share Antidilutive

Earnings Per Share Antidilutive Securities Excluded from Computation of EPS (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	0.2	1.3	0.9

Commitments And Contingencies (

Commitments And Contingencies (Details)	12 Months Ended
	Dec. 31, 2017USD ($)location	Dec. 31, 2016USD ($)location
Commitments and Contingencies Disclosure [Abstract]
Environmental liability	$ 58,000,000	$ 67,000,000
Current environmental liability	$ 15,000,000	$ 15,000,000
Known cleanup and remediation locations and projects | location	127	134
Number of sites - representative sample | location	15
Liability associated with those sites	$ 37,000,000
Environmental locations representative sample liability payout period, in years	5 years
Responsible locations with another party | location	13
Self-insured injury/damage to third party - up to	$ 50,000,000
Self-insured injury/damage to third parties - and above, per occurrence	1,100,000,000
Self-insured for bodily injury and property damage to third parties above, for specific perils	1,500,000,000
Self-insured NS owned property - up to	25,000,000
Self-insured NS owned property - and above, per occurrence	200,000,000
Purchase commitments	$ 1,100,000,000

Quarterly Financial Data (Detai

Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Railway operating revenues	$ 2,669	$ 2,670	$ 2,637	$ 2,575	$ 2,490	$ 2,524	$ 2,454	$ 2,420	$ 10,551	$ 9,888	$ 10,511
Income from railway operations	1,014	911	888	773	761	820	770	723	3,586	3,074	2,884
Net income	$ 3,968	$ 506	$ 497	$ 433	$ 416	$ 460	$ 405	$ 387	$ 5,404	$ 1,668	$ 1,556
Earnings per share:
Basic (in dollars per share)	$ 13.91	$ 1.76	$ 1.72	$ 1.49	$ 1.43	$ 1.56	$ 1.37	$ 1.30	$ 18.76	$ 5.66	$ 5.13
Diluted (in dollars per share)	$ 13.79	$ 1.75	$ 1.71	$ 1.48	$ 1.42	$ 1.55	$ 1.36	$ 1.29	18.61	$ 5.62	$ 5.10
Effect of Fourth Quarter Events [Line Items]
Tax Cuts and Jobs Act of 2017, income tax (expense) benefit, earnings per share, basic (in dollars per share)									12.21
Tax Cuts and Jobs Act of 2017, income tax (expense) benefit, earnings per share, diluted (in dollars per share)									$ 12.10
Purchased Services and Rent
Effect of Fourth Quarter Events [Line Items]
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit									$ 151
Income Taxes [Member]
Effect of Fourth Quarter Events [Line Items]
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit									3,331
Net Income [Member]
Effect of Fourth Quarter Events [Line Items]
Tax Cuts and Jobs Act of 2017, deferred tax liability, income tax (expense) benefit									$ 3,482

Schedule II - Valuation And Q87

Schedule II - Valuation And Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation Allowance (Included Net In Deferred Tax Liability) For Deferred Tax Assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance		$ 39	$ 35	$ 33
Expenses		5	4	2
Other Accounts		0	0	0
Deductions		0	0	0
Ending Balance		44	39	35
Casualty And Other Claims Included In Other Liabilities
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance		178	191	199
Expenses	[1]	83	68	66
Other Accounts		0	0	0
Deductions	[2]	82	81	74
Ending Balance		179	178	191
Current Portion Of Casualty And Other Claims Included In Accounts Payable
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance		192	174	187
Expenses		17	25	19
Other Accounts	[3]	124	101	119
Deductions	[4]	146	108	151
Ending Balance		$ 187	$ 192	$ 174
[1]	Includes adjustments for changes in estimates for prior years’ claims.
[2]	Payments and reclassifications to/from accounts payable.
[3]	Includes revenue refunds and overcharges provided through deductions from operating revenues and transfers from other accounts.
[4]	Payments and reclassifications to/from other liabilities.