Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The consolidated financial statements of Piedmont have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”), including the instructions to Form 10-Q and Article 10 of Regulation S-X, and do not include all of the information and footnotes required by U.S. generally accepted accounting principles (“GAAP”) for complete financial statements. In the opinion of management, the statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair presentation of the results for such periods. Results for these interim periods are not necessarily indicative of a full year’s results. Piedmont’s consolidated financial statements include the accounts of Piedmont, Piedmont’s wholly-owned subsidiaries, any variable interest entity ("VIE") of which Piedmont or any of its wholly-owned subsidiaries is considered to have the power to direct the activities of the entity and the obligation to absorb losses/right to receive benefits, or any entity in which Piedmont or any of its wholly-owned subsidiaries owns a controlling interest. In determining whether Piedmont or Piedmont OP has a controlling interest, the following factors, among others, are considered: equity ownership, voting rights, protective rights of investors, and participatory rights of investors. For further information, refer to the financial statements and footnotes included in Piedmont’s Annual Report on Form 10-K for the year ended December 31, 2014. All inter-company balances and transactions have been eliminated upon consolidation. Further, Piedmont has formed special purpose entities to acquire and hold real estate. Each special purpose entity is a separate legal entity and consequently the assets of the special purpose entities are not available to all creditors of Piedmont. The assets owned by these special purpose entities are being reported on a consolidated basis with Piedmont’s assets for financial reporting purposes only. Use of Estimates The preparation of the accompanying consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and notes. Actual results could differ from those estimates. Income Taxes Piedmont has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), and has operated as such, beginning with its taxable year ended December 31, 1998. To qualify as a REIT, Piedmont must meet certain organizational and operational requirements, including a requirement to distribute at least 90% of its annual REIT taxable income. As a REIT, Piedmont is generally not subject to federal income taxes. Piedmont is subject to certain taxes related to the operations of properties in certain locations, as well as operations conducted by its taxable REIT subsidiary, POH, which have been provided for in the financial statements. Recent Accounting Pronouncements The Financial Accounting Standards Board (the "FASB") has issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). The amendments in ASU 2014-09 change the criteria for the recognition of revenue to depict the transfer of promised 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 using a five-step determination process. Steps 1 through 5 involve (i) identifying contracts with a customer, (ii) identifying the performance obligations in the contract, (iii) determining the transaction price, (iv) allocating the transaction price to the performance obligations, and (v) recognizing revenue as an entity satisfies a performance obligation. Additionally, lease contracts are specifically excluded from ASU 2014-09. The amendments in ASU 2014-09 are effective in the first quarter of 2017 for Piedmont, and early adoption is not permitted. Piedmont is currently evaluating the potential impact, if any, of adoption. The FASB has issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810), Amendments to the Consolidation Analysis ("ASU 2015-02"). The amendments in ASU 2015-02 modifies the consolidation analysis of certain types of entities. Specifically, ASU 2015-02 changes the assessment criteria of whether limited partnerships are VIEs, eliminates the presumption that general partners should consolidate a limited partner, eliminates certain conditions from the evaluation of whether a fee paid to a decision maker constitutes a VIE, and changes the evaluation regarding the impact of related parties in the primary beneficiary determination of a VIE. The amendments in ASU 2015-02 are effective in the first quarter of 2016 for Piedmont, and Piedmont is currently evaluating the potential impact, if any, of adoption. The FASB has issued Accounting Standards Update No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30), Simplifying the Presentation of Debt Issuance Costs ("ASU 2015-03"). The amendments in ASU 2015-03 require debt issuance costs to be presented in the balance sheet as a reduction to the underlying debt instrument, as opposed to a separate asset. The amendments do not change the method by which such costs are amortized against earnings, nor do they change their classification in the consolidated statements of income, as a component of interest expense. The amendments in ASU 2015-03 are effective in the first quarter of 2016 for Piedmont, and Piedmont is currently evaluating the potential impact of adoption.

Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The consolidated financial statements of Piedmont have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”), including the instructions to Form 10-Q and Article 10 of Regulation S-X, and do not include all of the information and footnotes required by U.S. generally accepted accounting principles (“GAAP”) for complete financial statements. In the opinion of management, the statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair presentation of the results for such periods. Results for these interim periods are not necessarily indicative of a full year’s results.

Piedmont’s consolidated financial statements include the accounts of Piedmont, Piedmont’s wholly-owned subsidiaries, any variable interest entity ("VIE") of which Piedmont or any of its wholly-owned subsidiaries is considered to have the power to direct the activities of the entity and the obligation to absorb losses/right to receive benefits, or any entity in which Piedmont or any of its wholly-owned subsidiaries owns a controlling interest. In determining whether Piedmont or Piedmont OP has a controlling interest, the following factors, among others, are considered: equity ownership, voting rights, protective rights of investors, and participatory rights of investors. For further information, refer to the financial statements and footnotes included in Piedmont’s Annual Report on Form 10-K for the year ended December 31, 2014.

All inter-company balances and transactions have been eliminated upon consolidation.

Further, Piedmont has formed special purpose entities to acquire and hold real estate. Each special purpose entity is a separate legal entity and consequently the assets of the special purpose entities are not available to all creditors of Piedmont. The assets owned by these special purpose entities are being reported on a consolidated basis with Piedmont’s assets for financial reporting purposes only.

Use of Estimates

The preparation of the accompanying consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and notes. Actual results could differ from those estimates.

Income Taxes

Piedmont has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), and has operated as such, beginning with its taxable year ended December 31, 1998. To qualify as a REIT, Piedmont must meet certain organizational and operational requirements, including a requirement to distribute at least 90% of its annual REIT taxable income. As a REIT, Piedmont is generally not subject to federal income taxes. Piedmont is subject to certain taxes related to the operations of properties in certain locations, as well as operations conducted by its taxable REIT subsidiary, POH, which have been provided for in the financial statements.

Recent Accounting Pronouncements

The Financial Accounting Standards Board (the "FASB") has issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). The amendments in ASU 2014-09 change the criteria for the recognition of revenue to depict the transfer of promised 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 using a five-step determination process. Steps 1 through 5 involve (i) identifying contracts with a customer, (ii) identifying the performance obligations in the contract, (iii) determining the transaction price, (iv) allocating the transaction price to the performance obligations, and (v) recognizing revenue as an entity satisfies a performance obligation. Additionally, lease contracts are specifically excluded from ASU 2014-09. The amendments in ASU 2014-09 are effective in the first quarter of 2017 for Piedmont, and early adoption is not permitted. Piedmont is currently evaluating the potential impact, if any, of adoption.

The FASB has issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810), Amendments to the Consolidation Analysis ("ASU 2015-02"). The amendments in ASU 2015-02 modifies the consolidation analysis of certain types of entities. Specifically, ASU 2015-02 changes the assessment criteria of whether limited partnerships are VIEs, eliminates the presumption that general partners should consolidate a limited partner, eliminates certain conditions from the evaluation of whether a fee paid to a decision maker constitutes a VIE, and changes the evaluation regarding the impact of related parties in the primary beneficiary determination of a VIE. The amendments in ASU 2015-02 are effective in the first quarter of 2016 for Piedmont, and Piedmont is currently evaluating the potential impact, if any, of adoption.

The FASB has issued Accounting Standards Update No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30), Simplifying the Presentation of Debt Issuance Costs ("ASU 2015-03"). The amendments in ASU 2015-03 require debt issuance costs to be presented in the balance sheet as a reduction to the underlying debt instrument, as opposed to a separate asset. The amendments do not change the method by which such costs are amortized against earnings, nor do they change their classification in the consolidated statements of income, as a component of interest expense. The amendments in ASU 2015-03 are effective in the first quarter of 2016 for Piedmont, and Piedmont is currently evaluating the potential impact of adoption.