Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	(1) Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of Saia, Inc. and its wholly-owned subsidiaries (together, the Company or Saia). All significant intercompany accounts and transactions have been eliminated in the condensed consolidated financial statements. The condensed consolidated financial statements have been prepared by the Company without audit by the independent registered public accounting firm. In the opinion of management, all normal recurring adjustments necessary for a fair presentation of the condensed consolidated balance sheets, statements of operations and cash flows for the interim periods included herein have been made. These interim condensed consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information, the instructions to Quarterly Report on Form 10-Q and Rule 10-01 of Regulation S-X. Certain information and note disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles have been condensed or omitted from these statements. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. Operating results for the quarter and nine months ended are not necessarily indicative of the results of operations that may be expected for the year ended December 31, 2015. Business The Company offers customers a wide range of less-than-truckload, non-asset truckload, expedited and logistics services across the United States through its wholly-owned subsidiaries. Effective February 2, 2015, the Company’s subsidiaries were as follows: Saia Motor Freight Line, LLC, doing business as Saia LTL Freight; Saia TL Plus, LLC, formerly Robart Transportation, Inc.; Saia Sales, LLC; Saia Logistics Services, LLC, formerly The RL Services Group, LLC; Saia MetroGo, LLC, formed on January 22, 2015 and LinkEx, Inc. acquired on February 2, 2015. Accounting Pronouncements Adopted During 2015 In April 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2015-03, Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires entities to retrospectively classify debt issuance costs as a deduction from the corresponding liability on the balance sheet. In August 2015, the FASB issued ASU 2015-15 to clarify that debt issuance costs related to line-of-credit arrangements could continue to be presented as an asset and be subsequently amortized over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the arrangement. The Company adopted ASU 2015-03 as of September 30, 2015, which did not have an impact on our comparative consolidated balance sheets as the Company’s unamortized debt issuance costs at the time of adoption are related to line-of-credit arrangements. Accounting Pronouncements Not Yet Adopted In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services. The ASU will replace most existing revenue recognition guidance in U.S. generally accepted accounting principles when it becomes effective. In July 2015, the FASB updated ASU No. 2014-09 to defer the effective date by one year. The new standard is effective for the Company on January 1, 2018. Early application is permitted for the Company on January 1, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it completed its evaluation of the effect of the standard on its ongoing financial reporting.

(1) Summary of Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements include the accounts of Saia, Inc. and its wholly-owned subsidiaries (together, the Company or Saia). All significant intercompany accounts and transactions have been eliminated in the condensed consolidated financial statements.

The condensed consolidated financial statements have been prepared by the Company without audit by the independent registered public accounting firm. In the opinion of management, all normal recurring adjustments necessary for a fair presentation of the condensed consolidated balance sheets, statements of operations and cash flows for the interim periods included herein have been made. These interim condensed consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information, the instructions to Quarterly Report on Form 10-Q and Rule 10-01 of Regulation S-X. Certain information and note disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles have been condensed or omitted from these statements. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. Operating results for the quarter and nine months ended are not necessarily indicative of the results of operations that may be expected for the year ended December 31, 2015.

Business

The Company offers customers a wide range of less-than-truckload, non-asset truckload, expedited and logistics services across the United States through its wholly-owned subsidiaries. Effective February 2, 2015, the Company’s subsidiaries were as follows: Saia Motor Freight Line, LLC, doing business as Saia LTL Freight; Saia TL Plus, LLC, formerly Robart Transportation, Inc.; Saia Sales, LLC; Saia Logistics Services, LLC, formerly The RL Services Group, LLC; Saia MetroGo, LLC, formed on January 22, 2015 and LinkEx, Inc. acquired on February 2, 2015.

Accounting Pronouncements Adopted During 2015

In April 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2015-03, Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires entities to retrospectively classify debt issuance costs as a deduction from the corresponding liability on the balance sheet. In August 2015, the FASB issued ASU 2015-15 to clarify that debt issuance costs related to line-of-credit arrangements could continue to be presented as an asset and be subsequently amortized over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the arrangement. The Company adopted ASU 2015-03 as of September 30, 2015, which did not have an impact on our comparative consolidated balance sheets as the Company’s unamortized debt issuance costs at the time of adoption are related to line-of-credit arrangements.

Accounting Pronouncements Not Yet Adopted

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services. The ASU will replace most existing revenue recognition guidance in U.S. generally accepted accounting principles when it becomes effective. In July 2015, the FASB updated ASU No. 2014-09 to defer the effective date by one year. The new standard is effective for the Company on January 1, 2018. Early application is permitted for the Company on January 1, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it completed its evaluation of the effect of the standard on its ongoing financial reporting.