Regulatory Matters	3 Months Ended
Regulatory Matters	Mar. 31, 2018
Regulatory Matters	2:Regulatory Matters Regulatory matters are critical to Consumers. The Michigan Attorney General, ABATE, the MPSC Staff, and certain other parties typically participate in MPSC proceedings concerning Consumers, such as Consumers’ rate cases and PSCR and GCR processes. These parties often challenge various aspects of those proceedings, including the prudence of Consumers’ policies and practices, and seek cost disallowances and other relief. The parties also have appealed significant MPSC orders. Depending upon the specific issues, the outcomes of rate cases and proceedings, including judicial proceedings challenging MPSC orders or other actions, could negatively affect CMS Energy’s and Consumers’ liquidity, financial condition, and results of operations. Consumers cannot predict the outcome of these proceedings. There are multiple appeals pending that involve various issues concerning cost recovery from customers, the adequacy of the record evidence supporting the recovery of Smart Energy investments, and other matters. Consumers is unable to predict the outcome of these appeals. Electric Rate Case: In March 2017, Consumers filed an application with the MPSC seeking an annual rate increase of $173 million, based on a 10.5 percent authorized return on equity. The filing requested authority to recover new investment in system reliability, environmental compliance, and technology enhancements. In September 2017, Consumers reduced its requested annual rate increase to $148 million. In October 2017, Consumers self‑implemented an annual rate increase of $130 million, subject to refund with interest and potential penalties. The MPSC issued an order in March 2018, authorizing an annual rate increase of $66 million, based on a 10.0 percent authorized return on equity. Consumers had a recorded liability of $36 million for customer refunds at March 31, 2018. Gas Rate Case: In February 2018, the MPSC Staff filed testimony in the general gas rate case that Consumers filed in October 2017. In its testimony, the MPSC Staff recommended the disallowance of cost recovery for certain categories of historical capital expenditures incurred by Consumers, totaling over $115 million. A material disallowance of historical costs could negatively affect CMS Energy’s and Consumers’ results of operations. Consumers cannot predict the outcome of this proceeding. Tax Cuts and Jobs Act: The TCJA, which changed existing federal tax law and included numerous provisions that affect businesses, was signed into law in December 2017. Subsequently, the MPSC ordered all rate-regulated utilities in Michigan to report the impact that the new federal tax law will have on their customers. Consumers filed its response to the MPSC in January 2018, indicating that the TCJA reduces its annual electric revenue requirement by an estimated $116 million, and reduces its annual gas revenue requirement by an estimated $49 million. These amounts exclude potential refunds associated with Consumers’ remeasurement of its deferred income taxes. In February 2018, the MPSC ordered Consumers to file various proceedings to implement bill credits during 2018 in order to reflect the reduction in its annual electric and gas revenue requirements until customer rates are adjusted in conjunction with MPSC orders in Consumers’ general rate cases. Consumers filed the first of these proceedings in March 2018, requesting a $48 million reduction in its annual gas revenue requirement; it will file the remaining proceedings by September 2018. In anticipation of the proposed bill credits, Consumers had a $51 million recorded reserve for customer refunds at March 31, 2018. The MPSC’s February 2018 order also directed Consumers to file, by October 2018, additional proceedings to address the December 31, 2017 remeasurement of its deferred income taxes and any other impacts of the TCJA on customers. For additional details on the remeasurement, see Note 9, Income Taxes. Energy Waste Reduction Plan Incentive: Consumers will file its 2017 energy waste reduction reconciliation in May 2018, requesting the MPSC’s approval to collect from customers the maximum performance incentive of $31 million for exceeding its statutory savings targets in 2017. Consumers recognized incentive revenue under this program of $31 million in 2017.
Consumers Energy Company [Member]
Regulatory Matters	2:Regulatory Matters Regulatory matters are critical to Consumers. The Michigan Attorney General, ABATE, the MPSC Staff, and certain other parties typically participate in MPSC proceedings concerning Consumers, such as Consumers’ rate cases and PSCR and GCR processes. These parties often challenge various aspects of those proceedings, including the prudence of Consumers’ policies and practices, and seek cost disallowances and other relief. The parties also have appealed significant MPSC orders. Depending upon the specific issues, the outcomes of rate cases and proceedings, including judicial proceedings challenging MPSC orders or other actions, could negatively affect CMS Energy’s and Consumers’ liquidity, financial condition, and results of operations. Consumers cannot predict the outcome of these proceedings. There are multiple appeals pending that involve various issues concerning cost recovery from customers, the adequacy of the record evidence supporting the recovery of Smart Energy investments, and other matters. Consumers is unable to predict the outcome of these appeals. Electric Rate Case: In March 2017, Consumers filed an application with the MPSC seeking an annual rate increase of $173 million, based on a 10.5 percent authorized return on equity. The filing requested authority to recover new investment in system reliability, environmental compliance, and technology enhancements. In September 2017, Consumers reduced its requested annual rate increase to $148 million. In October 2017, Consumers self‑implemented an annual rate increase of $130 million, subject to refund with interest and potential penalties. The MPSC issued an order in March 2018, authorizing an annual rate increase of $66 million, based on a 10.0 percent authorized return on equity. Consumers had a recorded liability of $36 million for customer refunds at March 31, 2018. Gas Rate Case: In February 2018, the MPSC Staff filed testimony in the general gas rate case that Consumers filed in October 2017. In its testimony, the MPSC Staff recommended the disallowance of cost recovery for certain categories of historical capital expenditures incurred by Consumers, totaling over $115 million. A material disallowance of historical costs could negatively affect CMS Energy’s and Consumers’ results of operations. Consumers cannot predict the outcome of this proceeding. Tax Cuts and Jobs Act: The TCJA, which changed existing federal tax law and included numerous provisions that affect businesses, was signed into law in December 2017. Subsequently, the MPSC ordered all rate-regulated utilities in Michigan to report the impact that the new federal tax law will have on their customers. Consumers filed its response to the MPSC in January 2018, indicating that the TCJA reduces its annual electric revenue requirement by an estimated $116 million, and reduces its annual gas revenue requirement by an estimated $49 million. These amounts exclude potential refunds associated with Consumers’ remeasurement of its deferred income taxes. In February 2018, the MPSC ordered Consumers to file various proceedings to implement bill credits during 2018 in order to reflect the reduction in its annual electric and gas revenue requirements until customer rates are adjusted in conjunction with MPSC orders in Consumers’ general rate cases. Consumers filed the first of these proceedings in March 2018, requesting a $48 million reduction in its annual gas revenue requirement; it will file the remaining proceedings by September 2018. In anticipation of the proposed bill credits, Consumers had a $51 million recorded reserve for customer refunds at March 31, 2018. The MPSC’s February 2018 order also directed Consumers to file, by October 2018, additional proceedings to address the December 31, 2017 remeasurement of its deferred income taxes and any other impacts of the TCJA on customers. For additional details on the remeasurement, see Note 9, Income Taxes. Energy Waste Reduction Plan Incentive: Consumers will file its 2017 energy waste reduction reconciliation in May 2018, requesting the MPSC’s approval to collect from customers the maximum performance incentive of $31 million for exceeding its statutory savings targets in 2017. Consumers recognized incentive revenue under this program of $31 million in 2017.