Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2018
Summary of Significant Accounting Policies [Abstract]
Recent accounting prounouncements	Recently Adopted Accounting Pronouncements In May 2014, the FASB released updated guidance regarding the recognition of revenue from contracts with customers not otherwise addressed by specific guidance (commonly referred to as "ASC 606" or "the revenue recognition standard"). The core principle of the guidance is that an entity should recognize 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. To achieve that core principle, an entity should apply the following steps: (1) identify the contracts with the customer; (2) identify the performance obligations in the contract; (3) determine the contract price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. This guidance was effective for the Company on January 1, 2018. This guidance was required to be applied, at the Company's election, either (1) retrospectively to each prior reporting period presented or (2) under the modified retrospective method, with the cumulative effect being recognized at the date of initial application. The Company has elected to adopt the revenue recognition standard under the modified retrospective method, and the Company's adoption of the revenue recognition standard did not result in any adjustment to the balance of dividends/distributions in excess of earnings as of January 1, 2018. Given the nature of the Company’s contracts with customers, the Company’s pattern of revenue recognition is not impacted by the adoption of the revenue recognition standard. See note 4 for further discussion regarding the Company’s revenues. In November 2016, the FASB issued new guidance which requires an entity's statement of cash flows to explain the change in restricted cash and restricted cash equivalents in addition to cash and cash equivalents. This new guidance also requires an entity that includes cash, cash equivalents, restricted cash and restricted cash equivalents on multiple lines on its balance sheet to present a reconciliation between its statement of cash flows and its balance sheet. The Company adopted this guidance retrospectively, on January 1, 2018, and the impact of the new guidance is limited to certain changes in presentation on the condensed consolidated statement of cash flows and certain disclosures. See note 12. In January 2017, the FASB issued new guidance which clarifies the definition of a business in order to assist companies in evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. The Company adopted the guidance on January 1, 2018, and the adoption of this guidance did not have a material impact on its condensed consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued new guidance on the recognition, measurement, presentation and disclosure of leases. The new guidance requires lessees to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments for all leases with a term greater than 12 months. The accounting for lessors remains largely unchanged from existing guidance. This guidance is effective for the Company as of January 1, 2019 and is required to be applied using a modified retrospective approach for all leases existing at, or entered into after, the beginning of the earliest comparative period presented. Although early adoption is permitted, the Company does not expect to early adopt the new guidance prior to January 1, 2019. With regard to the application of this guidance to the Towers segment, the Company expects that (1) its Towers lessee arrangements will continue to be classified as operating leases under the new guidance; (2) this guidance will have a material impact on its condensed consolidated balance sheet due to the addition of right-of-use assets and lease liabilities for all lessee arrangements with a term greater than 12 months; and (3) there will not be a material impact to its condensed consolidated statement of operations and condensed consolidated statement of cash flows. With regard to the application of this guidance to the Fiber segment, the Company (1) has established and is progressing through the various steps of a cross-functional project plan to assess the impact of the standard; (2) expects this guidance to have a material impact on its condensed consolidated balance sheet due to the addition of right-of-use assets and lease liabilities for all lessee arrangements with a term greater than 12 months; and (3) continues to assess additional impacts to its condensed consolidated financial statements, including the condensed consolidated statement of operations and the condensed consolidated statement of cash flows.

Recently Adopted Accounting Pronouncements

In May 2014, the FASB released updated guidance regarding the recognition of revenue from contracts with customers not otherwise addressed by specific guidance (commonly referred to as "ASC 606" or "the revenue recognition standard"). The core principle of the guidance is that an entity should recognize 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. To achieve that core principle, an entity should apply the following steps: (1) identify the contracts with the customer; (2) identify the performance obligations in the contract; (3) determine the contract price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. This guidance was effective for the Company on January 1, 2018. This guidance was required to be applied, at the Company's election, either (1) retrospectively to each prior reporting period presented or (2) under the modified retrospective method, with the cumulative effect being recognized at the date of initial application.

The Company has elected to adopt the revenue recognition standard under the modified retrospective method, and the Company's adoption of the revenue recognition standard did not result in any adjustment to the balance of dividends/distributions in excess of earnings as of January 1, 2018. Given the nature of the Company’s contracts with customers, the Company’s pattern of revenue recognition is not impacted by the adoption of the revenue recognition standard.

See note 4 for further discussion regarding the Company’s revenues.

In November 2016, the FASB issued new guidance which requires an entity's statement of cash flows to explain the change in restricted cash and restricted cash equivalents in addition to cash and cash equivalents. This new guidance also requires an entity that includes cash, cash equivalents, restricted cash and restricted cash equivalents on multiple lines on its balance sheet to present a reconciliation between its statement of cash flows and its balance sheet. The Company adopted this guidance retrospectively, on January 1, 2018, and the impact of the new guidance is limited to certain changes in presentation on the condensed consolidated statement of cash flows and certain disclosures. See note 12.

In January 2017, the FASB issued new guidance which clarifies the definition of a business in order to assist companies in evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. The Company adopted the guidance on January 1, 2018, and the adoption of this guidance did not have a material impact on its condensed consolidated financial statements.

Recent Accounting Pronouncements Not Yet Adopted

In February 2016, the FASB issued new guidance on the recognition, measurement, presentation and disclosure of leases. The new guidance requires lessees to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments for all leases with a term greater than 12 months. The accounting for lessors remains largely unchanged from existing guidance. This guidance is effective for the Company as of January 1, 2019 and is required to be applied using a modified retrospective approach for all leases existing at, or entered into after, the beginning of the earliest comparative period presented. Although early adoption is permitted, the Company does not expect to early adopt the new guidance prior to January 1, 2019. With regard to the application of this guidance to the Towers segment, the Company expects that (1) its Towers lessee arrangements will continue to be classified as operating leases under the new guidance; (2) this guidance will have a material impact on its condensed consolidated balance sheet due to the addition of right-of-use assets and lease liabilities for all lessee arrangements with a term greater than 12 months; and (3) there will not be a material impact to its condensed consolidated statement of operations and condensed consolidated statement of cash flows. With regard to the application of this guidance to the Fiber segment, the Company (1) has established and is progressing through the various steps of a cross-functional project plan to assess the impact of the standard; (2) expects this guidance to have a material impact on its condensed consolidated balance sheet due to the addition of right-of-use assets and lease liabilities for all lessee arrangements with a term greater than 12 months; and (3) continues to assess additional impacts to its condensed consolidated financial statements, including the condensed consolidated statement of operations and the condensed consolidated statement of cash flows.