Rates and Other Regulatory Activities	9 Months Ended
Sep. 30, 2018
Regulated Operations [Abstract]
Rates and Other Regulatory Activities	Rates and Other Regulatory Activities Our natural gas and electric distribution operations in Delaware, Maryland and Florida are subject to regulation by their respective PSC; Eastern Shore, our natural gas transmission subsidiary, is subject to regulation by the FERC; and Peninsula Pipeline, our intrastate pipeline subsidiary, is subject to regulation by the Florida PSC. Chesapeake Utilities' Florida natural gas distribution division and FPU’s natural gas and electric distribution operations continue to be subject to regulation, as separate entities, by the Florida PSC. Delaware Effect of the TCJA on customers: The Delaware PSC issued an order requiring all rate-regulated utilities to file estimates of the impact of the TCJA on their cost of service for the most recent test year available (including new rate schedules). The order also required utilities to propose procedures for changing rates to reflect those impacts on or before March 31, 2018. Our Delaware Division filed the requisite reports with the Delaware PSC on March 30, 2018. Subsequently, the Delaware Division filed an updated report reflecting the impact of the TCJA on May 31, 2018. If, after reviewing the required filing, the Delaware PSC determines to reduce our rates, it will open a new docket and establish a procedural schedule for conducting an evidentiary hearing regarding the impacts of the TCJA on our operations and existing rates. In addition, on February 1, 2018, the Delaware PSC issued an order requiring Delaware rate-regulated public utilities to accrue regulatory liabilities reflecting the impacts of changes in the federal corporate income tax laws. In compliance with the Delaware PSC order, we have established a regulatory liability to reflect the estimated impacts of the changes in the federal corporate income tax rate. We believe that the reduction in rates charged by our Delaware Division because of the lower federal income taxes resulting from the TCJA will not have a material effect on our financial position or results of operations, because the reduction will be offset by an equal reduction in income tax expense. Underserved Area Rates: In December 2017, we filed an application requesting authorization to utilize existing expansion area tariff rates to serve customers located outside of the current Sussex County, Delaware expansion area boundaries that cannot be economically served under the regular tariff rates. In June 2018, we reached a settlement agreement with the relevant parties, which allows us to utilize higher rates for areas outside of our existing expansion area. The Delaware PSC unanimously approved the settlement at its public meeting on July 10, 2018. The new rate schedule became effective on August 1, 2018. CGS: In June 2018, we filed with the Delaware PSC an application requesting approval of the acquisition and subsequent conversion of propane to natural gas for certain CGS located within our territory. We requested the establishment of regulatory accounting treatment and valuation of the acquisition of certain CGS, approval of a methodology to set new distribution rates for CGS customers and approval of a new system-wide tariff rate that will recover CGS conversion costs. The Delaware PSC has not reached a decision as of the date of this filing. Maryland Division and Sandpiper Effect of the TCJA on customers: The Maryland PSC issued an order requiring all Maryland public utilities with rates explicitly grossed-up for income taxes to track the impacts of the TCJA, beginning January 1, 2018. The order required utilities to: (a) apply regulatory accounting treatment, which includes the use of regulatory assets and liabilities, for all impacts of the TCJA; (b) file an explanation of the expected effects of the TCJA on their expenses and revenues; and (c) explain when and how they expect to pass on to their customers the net results of those effects. We established a regulatory liability to reflect the impacts of the changes in the federal corporate income tax rate in compliance with the Maryland PSC’s order and made compliance filings that included preliminary estimates of the annual impact of the change in the statutory federal income tax rate. In April 2018, the Maryland PSC ordered both the Maryland Division and Sandpiper to implement reduced rates effective May 1, 2018, reflecting the impact of the TCJA. We implemented a one-time bill credit for the regulatory liability established for the refunds and issued the refunds to customers in July 2018. We submitted an informational filing to the Maryland PSC within the requisite 60 days of completing the refund payments. Additionally, if in the future the Maryland Division or Sandpiper identify any additional tax savings, we must submit an additional filing to the Maryland PSC in order to return those savings to customers as soon as possible. We believe that the reduction in rates charged by our Maryland Division and Sandpiper because of the lower federal income taxes resulting from the TCJA will not have a material effect on our financial position or results of operations, because the reduction is offset by an equal reduction in income tax expense. Florida Florida Electric Reliability/Modernization Pilot Program: In July 2017, our Florida electric operations filed a petition with the Florida PSC requesting approval to include $15.2 million of certain capital project expenditures in its rate base and to adjust its base rates accordingly. These expenditures are designed to improve the stability and safety of the electric system, while enhancing the capability of our electrical grid. An interconnection project with FPL, which enables us to mitigate fuel costs for our electric customers, was included in the $15.2 million capital project expenditures. In December 2017, the Florida PSC approved this petition, effective January 1, 2018. The settlement agreement prescribed the methodology for adjusting the new rates based on the lower federal income tax rate and the process and methodology regarding the refund of deferred income taxes, reclassified as a regulatory liability, as a result of the TCJA. We have established a regulatory liability to reflect the impacts of the changes in the federal corporate income tax rate in compliance with the settlement agreement. Electric Limited Proceeding-Storm Recovery: In February 2018, our Florida electric operations filed a petition with the Florida PSC, requesting recovery of incremental storm restoration costs related to several hurricanes and tropical storms, along with the replenishment of storm reserve to its pre-storm level of $1.5 million. As a result of these hurricanes and tropical storms, our Florida electric operation’s storm reserve was depleted and is currently at a deficit of $779,000. We have requested approval of a surcharge of $1.82 per kilowatt per hour for two years to recover and replenish storm-related costs. This matter is scheduled for review at the Florida PSC’s meeting in the fourth quarter of 2018. Effect of the TCJA on customers: The Office of Public Counsel filed a petition requesting that the Florida PSC establish a general docket to investigate and adjust rates for all investor-owned utilities related to the passage of the TCJA. The Florida PSC issued a Memorandum with a recommendation that, if utilities do not agree to a January 1, 2018 effective date, then the effective date should be February 6, 2018. On January 30, 2018, the Florida PSC scheduled informal meetings between its staff and interested persons to discuss the impact of the TCJA. Hearings for Florida’s electric utilities are tentatively scheduled for the first quarter of 2019, and hearings for the natural gas utilities are tentatively scheduled for the fourth quarter of 2018. In December 2017, the Florida PSC issued an order regarding the limited proceeding for our Florida electric operations, which prescribes the applicability, timing and treatment of the impacts of the TCJA, as discussed above. In June, our Florida natural gas operations filed petitions and testimony in support of the disposition of the impacts created by the TCJA. We believe that the reduction in rates charged by our Florida electric and natural gas operations because of the lower federal income taxes resulting from the TCJA will not have a material effect on our financial position or results of operations, because the reduction is offset by an equal reduction in income tax expense. In October 18, 2018, our electric distribution operation reached a settlement agreement with the Office of Public Counsel. This settlement agreement was filed for approval with the Florida PSC on October 19, 2018 and hearing in this action is expected to be held in December 2018. This agreement proposes that our electric distribution operation will flow benefit associated with the TCJA back to its customers through a combination of reductions to the fuel cost recovery rate, base rates, as well as application to the storm reserve over the next several years. Eastern Shore 2017 Expansion Project: In May 2016, the FERC approved Eastern Shore's request to initiate the pre-filing review process for its 2017 Expansion Project. The 2017 Expansion Project's facilities include approximately 23 miles of pipeline looping in Pennsylvania, Maryland and Delaware; upgrades to existing metering facilities in Lancaster County, Pennsylvania; installation of an additional compressor unit at Eastern Shore’s existing Daleville compressor station in Chester County, Pennsylvania; and approximately 17 miles of new mainline extension and two pressure control stations in Sussex County, Delaware. Eastern Shore entered into precedent agreements with seven existing customers, including three affiliates of Chesapeake Utilities, for a total of 61,162 Dts/d of additional firm natural gas transportation service on Eastern Shore’s pipeline system with an additional 52,500 Dts/d of firm transportation service at certain Eastern Shore receipt facilities. In October 2017, the FERC issued a CP authorizing Eastern Shore to construct the expansion facilities. The estimated cost of the 2017 Expansion Project is approximately $117.0 million. Eastern Shore submitted its Implementation Plan in October 2017, addressing the actions Eastern Shore will undertake to meet the environmental conditions set forth in the FERC's order. In December 2017, the TETLP interconnect upgrade was placed into service. In June 2018, the Fair Hill Loop in Chester County, Pennsylvania and Cecil County, Maryland was placed into service. With the exception of some minor facilities, the remaining segments of the 2017 Expansion Project are expected to be placed into service in various phases during the fourth quarter of 2018. 2017 Rate Case Filing: In January 2017, Eastern Shore filed a base rate proceeding with the FERC, as required by the terms of its 2012 rate case settlement agreement. Eastern Shore based its proposed rates on the mainline cost of service of approximately $60.0 million resulting in an overall requested annual revenue increase of approximately $18.9 million and a requested rate of return on common equity of 13.75 percent. In March 2017, the FERC issued an order suspending the tariff rates for the usual five-month period. In August 2017, Eastern Shore implemented new rates, subject to refund, based on the outcome of the rate proceeding. Eastern Shore recorded incremental revenue of approximately $3.7 million for the year ended December 31, 2017, and established a regulatory liability to reserve a portion of the total incremental revenues generated by the new rates pending FERC approval of the settlement and refunds to customers according to the terms of the settlement agreement. The FERC approved the settlement agreement in February 2018, and it became final in March 2018. Exclusive of the TCJA impact, base rates would have increased, on an annual basis, by approximately $9.8 million. Effect of the TCJA on customers: In March 2018, Eastern Shore filed with the FERC its revised base rates, reflecting the change in its federal corporate income tax rate. These adjusted base rates became effective April 1, 2018 and will generate approximately $6.6 million in incremental margin, on an annual basis. Any excess accumulated deferred income tax balances will flow back to customers over the period determined in the next rate case, absent any transition rule included in the TCJA or other statutes or rules that would govern the flow-back period. In April 2018, Eastern Shore refunded to its customers, with interest, the difference between the proposed rates and the settlement rates. The refund to customers also reflected the difference in rates due to the impact of the TCJA. In March 2018, the FERC issued a NOPR that proposed a process to determine which natural gas pipelines may be collecting unjust and unreasonable rates in light of the recent reduction in the corporate income tax rate in the TCJA and changes to the FERC’s income tax allowance policies following the United Airlines, Inc. v. FERC decision. The NOPR proposed requiring interstate natural gas pipelines to provide an informational filing to allow the FERC to evaluate the impact of the TCJA on the pipelines’ revenue requirement. In April 2018, Eastern Shore filed comments in this proceeding requesting confirmation that Eastern Shore is not required to provide an informational filing because it has already implemented lower rates in accordance with the settlement agreement in its 2017 rate case approved by the FERC. In July 2018, the FERC issued a final rule, which largely adopted the process proposed in the NOPR, requiring all interstate natural gas companies to file an informational filing for the purpose of evaluating the impact of the TCJA and the United Airlines, Inc. v. FERC decision on interstate natural gas pipelines’ revenue requirements. The final rule provides that an individual pipeline has the option to request a waiver if the pre-March 2018 settlement justifies not adjusting its rates at this time. In September 2018, Eastern Shore requested that the FERC grant it a waiver of the requirement. In October 2018, the FERC issued an order granting the waiver. Del-Mar Energy Pathway Project: In September 2018, Eastern Shore filed a Certificate Application for the Del-Mar Energy Pathway project with the FERC. The proposed project would provide an additional 14,300 Dts/d of capacity to four customers. Facilities to be constructed include six miles of pipeline looping in Delaware, 13 miles of new mainline extension in Sussex County, Delaware and Somerset County, Maryland as well as new pressure control and delivery stations in these counties. The benefits of this project include (i) further natural gas transmission pipeline infrastructure in eastern Sussex County, Delaware and (ii) first extension of Eastern Shore’s pipeline system into Somerset County, Maryland.

Rates and Other Regulatory Activities

Our natural gas and electric distribution operations in Delaware, Maryland and Florida are subject to regulation by their respective PSC; Eastern Shore, our natural gas transmission subsidiary, is subject to regulation by the FERC; and Peninsula Pipeline, our intrastate pipeline subsidiary, is subject to regulation by the Florida PSC. Chesapeake Utilities' Florida natural gas distribution division and FPU’s natural gas and electric distribution operations continue to be subject to regulation, as separate entities, by the Florida PSC.

Delaware

Effect of the TCJA on customers: The Delaware PSC issued an order requiring all rate-regulated utilities to file estimates of the impact of the TCJA on their cost of service for the most recent test year available (including new rate schedules). The order also required utilities to propose procedures for changing rates to reflect those impacts on or before March 31, 2018. Our Delaware Division filed the requisite reports with the Delaware PSC on March 30, 2018. Subsequently, the Delaware Division filed an updated report reflecting the impact of the TCJA on May 31, 2018. If, after reviewing the required filing, the Delaware PSC determines to reduce our rates, it will open a new docket and establish a procedural schedule for conducting an evidentiary hearing regarding the impacts of the TCJA on our operations and existing rates.

In addition, on February 1, 2018, the Delaware PSC issued an order requiring Delaware rate-regulated public utilities to accrue regulatory liabilities reflecting the impacts of changes in the federal corporate income tax laws. In compliance with the Delaware PSC order, we have established a regulatory liability to reflect the estimated impacts of the changes in the federal corporate income tax rate. We believe that the reduction in rates charged by our Delaware Division because of the lower federal income taxes resulting from the TCJA will not have a material effect on our financial position or results of operations, because the reduction will be offset by an equal reduction in income tax expense.

Underserved Area Rates: In December 2017, we filed an application requesting authorization to utilize existing expansion area tariff rates to serve customers located outside of the current Sussex County, Delaware expansion area boundaries that cannot be economically served under the regular tariff rates. In June 2018, we reached a settlement agreement with the relevant parties, which allows us to utilize higher rates for areas outside of our existing expansion area. The Delaware PSC unanimously approved the settlement at its public meeting on July 10, 2018. The new rate schedule became effective on August 1, 2018.

CGS: In June 2018, we filed with the Delaware PSC an application requesting approval of the acquisition and subsequent conversion of propane to natural gas for certain CGS located within our territory. We requested the establishment of regulatory accounting treatment and valuation of the acquisition of certain CGS, approval of a methodology to set new distribution rates for CGS customers and approval of a new system-wide tariff rate that will recover CGS conversion costs. The Delaware PSC has not reached a decision as of the date of this filing.

Maryland Division and Sandpiper

Effect of the TCJA on customers: The Maryland PSC issued an order requiring all Maryland public utilities with rates explicitly grossed-up for income taxes to track the impacts of the TCJA, beginning January 1, 2018. The order required utilities to: (a) apply regulatory accounting treatment, which includes the use of regulatory assets and liabilities, for all impacts of the TCJA; (b) file an explanation of the expected effects of the TCJA on their expenses and revenues; and (c) explain when and how they expect to pass on to their customers the net results of those effects. We established a regulatory liability to reflect the impacts of the changes in the federal corporate income tax rate in compliance with the Maryland PSC’s order and made compliance filings that included preliminary estimates of the annual impact of the change in the statutory federal income tax rate. In April 2018, the Maryland PSC ordered both the Maryland Division and Sandpiper to implement reduced rates effective May 1, 2018, reflecting the impact of the TCJA. We implemented a one-time bill credit for the regulatory liability established for the refunds and issued the refunds to customers in July 2018. We submitted an informational filing to the Maryland PSC within the requisite 60 days of completing the refund payments. Additionally, if in the future the Maryland Division or Sandpiper identify any additional tax savings, we must submit an additional filing to the Maryland PSC in order to return those savings to customers as soon as possible. We believe that the reduction in rates charged by our Maryland Division and Sandpiper because of the lower federal income taxes resulting from the TCJA will not have a material effect on our financial position or results of operations, because the reduction is offset by an equal reduction in income tax expense.

Florida

Florida Electric Reliability/Modernization Pilot Program: In July 2017, our Florida electric operations filed a petition with the Florida PSC requesting approval to include $15.2 million of certain capital project expenditures in its rate base and to adjust its base rates accordingly. These expenditures are designed to improve the stability and safety of the electric system, while enhancing the capability of our electrical grid. An interconnection project with FPL, which enables us to mitigate fuel costs for our electric customers, was included in the $15.2 million capital project expenditures. In December 2017, the Florida PSC approved this petition, effective January 1, 2018. The settlement agreement prescribed the methodology for adjusting the new rates based on the lower federal income tax rate and the process and methodology regarding the refund of deferred income taxes, reclassified as a regulatory liability, as a result of the TCJA. We have established a regulatory liability to reflect the impacts of the changes in the federal corporate income tax rate in compliance with the settlement agreement.

Electric Limited Proceeding-Storm Recovery: In February 2018, our Florida electric operations filed a petition with the Florida PSC, requesting recovery of incremental storm restoration costs related to several hurricanes and tropical storms, along with the replenishment of storm reserve to its pre-storm level of $1.5 million. As a result of these hurricanes and tropical storms, our Florida electric operation’s storm reserve was depleted and is currently at a deficit of $779,000. We have requested approval of a surcharge of $1.82 per kilowatt per hour for two years to recover and replenish storm-related costs. This matter is scheduled for review at the Florida PSC’s meeting in the fourth quarter of 2018.

Effect of the TCJA on customers: The Office of Public Counsel filed a petition requesting that the Florida PSC establish a general docket to investigate and adjust rates for all investor-owned utilities related to the passage of the TCJA. The Florida PSC issued a Memorandum with a recommendation that, if utilities do not agree to a January 1, 2018 effective date, then the effective date should be February 6, 2018. On January 30, 2018, the Florida PSC scheduled informal meetings between its staff and interested persons to discuss the impact of the TCJA. Hearings for Florida’s electric utilities are tentatively scheduled for the first quarter of 2019, and hearings for the natural gas utilities are tentatively scheduled for the fourth quarter of 2018.

In December 2017, the Florida PSC issued an order regarding the limited proceeding for our Florida electric operations, which prescribes the applicability, timing and treatment of the impacts of the TCJA, as discussed above. In June, our Florida natural gas operations filed petitions and testimony in support of the disposition of the impacts created by the TCJA. We believe that the reduction in rates charged by our Florida electric and natural gas operations because of the lower federal income taxes resulting from the TCJA will not have a material effect on our financial position or results of operations, because the reduction is offset by an equal reduction in income tax expense.

In October 18, 2018, our electric distribution operation reached a settlement agreement with the Office of Public Counsel. This settlement agreement was filed for approval with the Florida PSC on October 19, 2018 and hearing in this action is expected to be held in December 2018. This agreement proposes that our electric distribution operation will flow benefit associated with the TCJA back to its customers through a combination of reductions to the fuel cost recovery rate, base rates, as well as application to the storm reserve over the next several years.

Eastern Shore

2017 Expansion Project: In May 2016, the FERC approved Eastern Shore's request to initiate the pre-filing review process for its 2017 Expansion Project. The 2017 Expansion Project's facilities include approximately 23 miles of pipeline looping in Pennsylvania, Maryland and Delaware; upgrades to existing metering facilities in Lancaster County, Pennsylvania; installation of an additional compressor unit at Eastern Shore’s existing Daleville compressor station in Chester County, Pennsylvania; and approximately 17 miles of new mainline extension and two pressure control stations in Sussex County, Delaware. Eastern Shore entered into precedent agreements with seven existing customers, including three affiliates of Chesapeake Utilities, for a total of 61,162 Dts/d of additional firm natural gas transportation service on Eastern Shore’s pipeline system with an additional 52,500 Dts/d of firm transportation service at certain Eastern Shore receipt facilities.

In October 2017, the FERC issued a CP authorizing Eastern Shore to construct the expansion facilities. The estimated cost of the 2017 Expansion Project is approximately $117.0 million. Eastern Shore submitted its Implementation Plan in October 2017, addressing the actions Eastern Shore will undertake to meet the environmental conditions set forth in the FERC's order.

In December 2017, the TETLP interconnect upgrade was placed into service. In June 2018, the Fair Hill Loop in Chester County, Pennsylvania and Cecil County, Maryland was placed into service. With the exception of some minor facilities, the remaining segments of the 2017 Expansion Project are expected to be placed into service in various phases during the fourth quarter of 2018.

2017 Rate Case Filing: In January 2017, Eastern Shore filed a base rate proceeding with the FERC, as required by the terms of its 2012 rate case settlement agreement. Eastern Shore based its proposed rates on the mainline cost of service of approximately $60.0 million resulting in an overall requested annual revenue increase of approximately $18.9 million and a requested rate of return on common equity of 13.75 percent. In March 2017, the FERC issued an order suspending the tariff rates for the usual five-month period.

In August 2017, Eastern Shore implemented new rates, subject to refund, based on the outcome of the rate proceeding. Eastern Shore recorded incremental revenue of approximately $3.7 million for the year ended December 31, 2017, and established a regulatory liability to reserve a portion of the total incremental revenues generated by the new rates pending FERC approval of the settlement and refunds to customers according to the terms of the settlement agreement. The FERC approved the settlement agreement in February 2018, and it became final in March 2018. Exclusive of the TCJA impact, base rates would have increased, on an annual basis, by approximately $9.8 million.

Effect of the TCJA on customers: In March 2018, Eastern Shore filed with the FERC its revised base rates, reflecting the change in its federal corporate income tax rate. These adjusted base rates became effective April 1, 2018 and will generate approximately $6.6 million in incremental margin, on an annual basis. Any excess accumulated deferred income tax balances will flow back to customers over the period determined in the next rate case, absent any transition rule included in the TCJA or other statutes or rules that would govern the flow-back period. In April 2018, Eastern Shore refunded to its customers, with interest, the difference between the proposed rates and the settlement rates. The refund to customers also reflected the difference in rates due to the impact of the TCJA.

In March 2018, the FERC issued a NOPR that proposed a process to determine which natural gas pipelines may be collecting unjust and unreasonable rates in light of the recent reduction in the corporate income tax rate in the TCJA and changes to the FERC’s income tax allowance policies following the United Airlines, Inc. v. FERC decision. The NOPR proposed requiring interstate natural gas pipelines to provide an informational filing to allow the FERC to evaluate the impact of the TCJA on the pipelines’ revenue requirement. In April 2018, Eastern Shore filed comments in this proceeding requesting confirmation that Eastern Shore is not required to provide an informational filing because it has already implemented lower rates in accordance with the settlement agreement in its 2017 rate case approved by the FERC. In July 2018, the FERC issued a final rule, which largely adopted the process proposed in the NOPR, requiring all interstate natural gas companies to file an informational filing for the purpose of evaluating the impact of the TCJA and the United Airlines, Inc. v. FERC decision on interstate natural gas pipelines’ revenue requirements. The final rule provides that an individual pipeline has the option to request a waiver if the pre-March 2018 settlement justifies not adjusting its rates at this time. In September 2018, Eastern Shore requested that the FERC grant it a waiver of the requirement. In October 2018, the FERC issued an order granting the waiver.

Del-Mar Energy Pathway Project: In September 2018, Eastern Shore filed a Certificate Application for the Del-Mar Energy Pathway project with the FERC. The proposed project would provide an additional 14,300 Dts/d of capacity to four customers. Facilities to be constructed include six miles of pipeline looping in Delaware, 13 miles of new mainline extension in Sussex County, Delaware and Somerset County, Maryland as well as new pressure control and delivery stations in these counties. The benefits of this project include (i) further natural gas transmission pipeline infrastructure in eastern Sussex County, Delaware and (ii) first extension of Eastern Shore’s pipeline system into Somerset County, Maryland.