Basis of Presentation (Policies)	9 Months Ended
Basis of Presentation (Policies)	Sep. 30, 2014
Accounting Policies [Abstract]
Consolidation, Policy	The accompanying Condensed Consolidated Financial Statements represent United Stationers Inc. (“USI”) with its wholly owned subsidiary United Stationers Supply Co. (“USSC”), and USSC’s subsidiaries (collectively, “United” or the “Company”). The Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States and include the accounts of USI and its subsidiaries. All intercompany transactions and balances have been eliminated. The Company operates in a single reportable segment as a leading distributor of business essentials. The accompanying Condensed Consolidated Financial Statements are unaudited, except for the Condensed Consolidated Balance Sheet as of December 31, 2013, which was derived from the December 31, 2013 audited financial statements. The Condensed Consolidated Financial Statements have been prepared in accordance with the rules and regulations of the United States Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements, prepared in accordance with accounting principles generally accepted in the United States, have been condensed or omitted pursuant to such rules and regulations. Accordingly, the reader of this Quarterly Report on Form 10-Q should refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2013 for further information. In the opinion of management, the accompanying unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, necessary to present fairly the financial position of United at September 30, 2014 and the results of operations and cash flows for the nine months ended September 30, 2014 and 2013. The results of operations for the three months and nine months ended September 30, 2014 should not necessarily be taken as indicative of the results of operations that may be expected for the entire year.
Inventory	Inventory Approximately 74% and 76% of total inventory as of September 30, 2014 and December 31, 2013, respectively has been valued under the last-in, first-out (“LIFO”) accounting method. The remaining inventory is valued under the first-in, first-out (“FIFO”) accounting method. Inventory valued under the FIFO and LIFO accounting methods is recorded at the lower of cost or market. If the Company had valued its entire inventory under the lower of FIFO cost or market, inventory would have been $117.3 million and $112.4 million higher than reported as of September 30, 2014 and December 31, 2013, respectively. The nine-month change in the LIFO reserve as of September 30, 2014 resulted in a $4.9 million increase in cost of goods sold which included a LIFO liquidation relating to decrements in the Company’s office products and furniture pools. These decrements resulted in liquidation of LIFO inventory quantities carried at lower costs in prior years as compared with the cost of current year purchases. This liquidation resulted in LIFO income of $3.4 million, which was more than offset by LIFO expense of $8.3 million related to current inflation.
New Accounting Pronouncements	New Accounting Pronouncements In June 2014, the FASB issued ASU No. 2014-12, Compensation—Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved After the Requisite Service Period. The standard requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition, and compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved. This ASU is effective for fiscal years beginning after December 15, 2015, and for interim periods within those fiscal years. This new standard will not have an effect on the Company’s consolidated financial statements as it is in alignment with the Company’s current accounting policies for equity based compensation. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue From Contracts With Customers, that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. This standard is effective for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently evaluating the new guidance to determine the impact it will have on its consolidated financial statements. In July 2013, the FASB issued Accounting Standards Update No. 2013-11, Income Taxes (Topic 740) - Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (ASU 2013-11). This ASU requires that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, be presented in the financial statements as either a reduction to a deferred tax asset or separately as a liability depending on the existence, availability and/or use of an operating loss carry forward, a similar tax loss, or a tax credit carry forward. This ASU was effective for the Company beginning in the first quarter of 2014. There was no impact on the Company’s financial condition or results of operations due to the adoption of this standard.

Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

+ References+ Details

- Definition

Disclosure of accounting policy for major classes of inventories, bases of stating inventories (for example, lower of cost or market), methods by which amounts are added and removed from inventory classes (for example, FIFO, LIFO, or average cost), loss recognition on impairment of inventories, and situations in which inventories are stated above cost. If inventory is carried at cost, this disclosure includes the nature of the cost elements included in inventory.

+ References+ Details