Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2016
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, 2015. Operating results for the quarter ended March 31, 2016 are not necessarily indicative of the results of operations that may be expected for the year ended December 31, 2016. 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. The Company’s subsidiaries are 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. The Company has one operating segment. Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), a leasing standard for both lessees and lessors. Under its core principle, a lessee will recognize lease assets and liabilities on the balance sheet for all arrangements with terms longer than 12 months. Lessor accounting remains largely consistent with existing U.S. generally accepted accounting principles. The new standard is effective for the Company on January 1, 2019. Early adoption is permitted. The standard requires the use of a modified retrospective transition method. The Company is evaluating the effect that ASU No. 2016-02 will have on its consolidated financial statements and related disclosures. The Company has not completed its evaluation of the effect of the standard on its ongoing financial reporting. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which requires entities to recognize the income tax effects of stock awards in the income statement when the awards vest or are settled. Further, the ASU allows entities to withhold up to the maximum individual statutory tax rate without classifying the stock awards as a liability and to account for forfeitures either upon occurrence or by estimating forfeitures. The new standard is effective for the Company on January 1, 2017. Early adoption is permitted. The Company is evaluating the effect that ASU No. 2016-09 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, 2015. Operating results for the quarter ended March 31, 2016 are not necessarily indicative of the results of operations that may be expected for the year ended December 31, 2016.

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. The Company’s subsidiaries are 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. The Company has one operating segment.

Accounting Pronouncements Not Yet Adopted

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), a leasing standard for both lessees and lessors. Under its core principle, a lessee will recognize lease assets and liabilities on the balance sheet for all arrangements with terms longer than 12 months. Lessor accounting remains largely consistent with existing U.S. generally accepted accounting principles. The new standard is effective for the Company on January 1, 2019. Early adoption is permitted. The standard requires the use of a modified retrospective transition method. The Company is evaluating the effect that ASU No. 2016-02 will have on its consolidated financial statements and related disclosures. The Company has not completed its evaluation of the effect of the standard on its ongoing financial reporting.

In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which requires entities to recognize the income tax effects of stock awards in the income statement when the awards vest or are settled. Further, the ASU allows entities to withhold up to the maximum individual statutory tax rate without classifying the stock awards as a liability and to account for forfeitures either upon occurrence or by estimating forfeitures. The new standard is effective for the Company on January 1, 2017. Early adoption is permitted. The Company is evaluating the effect that ASU No. 2016-09 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.