Commitments and Contingencies	9 Months Ended
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation, Claims and Assessments In March 2009, a stockholder brought suit, Bennett v. Sprint Nextel Corp., in the U.S. District Court for the District of Kansas, alleging that Sprint Communications and three of its former officers violated Section 10(b) of the Exchange Act and Rule 10b-5 by failing adequately to disclose certain alleged operational difficulties subsequent to the Sprint-Nextel merger, and by purportedly issuing false and misleading statements regarding the write-down of goodwill. The district court granted final approval of a settlement in August 2015, which did not have a material impact to our financial statements. Five stockholder derivative suits related to this 2009 stockholder suit were filed against Sprint Communications and certain of its present and/or former officers and directors. The first, Murphy v. Forsee, was filed in state court in Kansas on April 8, 2009, was removed to federal court, and was stayed by the court pending resolution of the motion to dismiss the Bennett case; the second, Randolph v. Forsee, was filed on July 15, 2010 in state court in Kansas, was removed to federal court, and was remanded back to state court; the third, Ross-Williams v. Bennett, et al., was filed in state court in Kansas on February 1, 2011; the fourth, Price v. Forsee, et al., was filed in state court in Kansas on April 15, 2011; and the fifth, Hartleib v. Forsee, et al., was filed in federal court in Kansas on July 14, 2011. These cases were essentially stayed while the Bennett case was pending, and we have reached an agreement in principle to settle the matters, by agreeing to some governance provisions and by paying plaintiffs' attorneys fees in an immaterial amount. The court approved the settlement but reduced the plaintiffs' attorneys fees. On April 27, 2018, the court of appeals for the state of Kansas affirmed the settlement ruling. On May 30, 2018, plaintiffs filed a Petition for Review with the Supreme Court of Kansas. On November 21, 2018, the Supreme Court of Kansas denied the Petition for Review, which concluded the case. On April 19, 2012, the New York Attorney General filed a complaint alleging that Sprint Communications had fraudulently failed to collect and pay more than $100 million in New York sales taxes on receipts from its sale of wireless telephone services since July 2005. The complaint also sought recovery of triple damages under the State False Claims Act, as well as penalties and interest. Sprint Communications moved to dismiss the complaint on June 14, 2012. On July 1, 2013, the court entered an order denying the motion to dismiss in large part, although it did dismiss certain counts or parts of certain counts. Sprint Communications appealed that order and the intermediate appellate court affirmed the order of the trial court. On October 20, 2015, the Court of Appeals of New York affirmed the decision of the appellate court that the tax statute required us to collect and remit the disputed taxes. Our petition for certiorari to the U.S. Supreme Court on grounds of federal preemption was denied. We previously paid the principal amount of tax at issue, under protest, while the suit was pending. On December 21, 2018, Sprint Communications and the State of New York settled the dispute, as well as an unrelated tax matter. As a result, the Company recognized an additional $50 million of litigation expense during the three-month period ended December 31, 2018. Eight related stockholder derivative suits have been filed against Sprint Communications and certain of its current and former officers and directors. Each suit alleges generally that the individual defendants breached their fiduciary duties to Sprint Communications and its stockholders by allegedly permitting, and failing to disclose, the actions alleged in the suit filed by the New York Attorney General. One suit, filed by the Louisiana Municipal Police Employees Retirement System, was dismissed by a federal court. Two suits were filed in state court in Johnson County, Kansas and one of those suits was dismissed as premature; and five suits are pending in federal court in Kansas. The remaining Kansas suits have been stayed pending resolution of the Attorney General's suit. We do not expect the resolution of these matters to have a material adverse effect on our financial position or results of operations. On October 9, 2018, October 18, 2018, and October 24, 2018, three purported stockholders of Sprint commenced actions, captioned Klein v. Sprint Corporation et al., Muehlgay v. Sprint Corporation et al., and Binns Blount v. Sprint Corporation et al., in the United States District Court for the District of Delaware. The complaints name Sprint and the members of the Sprint board of directors as defendants. The complaints asserted claims under Section 14(a) and Section 20(a) of the Exchange Act challenging the adequacy of the disclosures relating to the proposed merger transactions with T-Mobile made in the associated joint consent solicitation statement/prospectus. The complaints sought, among other relief, an injunction preventing the parties from consummating the merger transactions, damages in the event the merger transactions are consummated, and the award of attorneys’ fees. On October 29, 2018, the plaintiff in the Binns Blount action filed a notice voluntarily dismissing their complaint without prejudice. On December 27, 2018, the Klein case was dismissed. On January 4, 2019, the Muehlgay case was dismissed. Sprint is currently involved in numerous court actions alleging that Sprint is infringing various patents. Most of these cases effectively seek only monetary damages. A small number of these cases are brought by companies that sell products and seek injunctive relief as well. These cases have progressed to various degrees and a small number may go to trial if they are not otherwise resolved. Adverse resolution of these cases could require us to pay significant damages, cease certain activities, or cease selling the relevant products and services. In many circumstances, we would be indemnified for monetary losses that we incur with respect to the actions of our suppliers or service providers. We do not expect the resolution of these cases to have a material adverse effect on our financial position or results of operations. In October 2013, the FCC Enforcement Bureau began to issue notices of apparent liability (NALs) to other Lifeline providers, imposing fines for intracarrier duplicate accounts identified by the government during its audit function. Those audits also identified a small percentage of potentially duplicative intracarrier accounts related to our Assurance Wireless^® business. No NAL has yet been issued with respect to Sprint and we do not know if one will be issued. Further, we are not able to reasonably estimate the amount of any claim for penalties that might be asserted. However, based on the information currently available, if a claim is asserted by the FCC, Sprint does not believe that any amount ultimately paid would be material to the Company’s results of operations or financial position. Various other suits, inquiries, proceedings and claims, either asserted or unasserted, including purported class actions typical for a large business enterprise and intellectual property matters, are possible or pending against us or our subsidiaries. If our interpretation of certain laws or regulations, including those related to various federal or state matters such as sales, use or property taxes, or other charges were found to be mistaken, it could result in payments by us. While it is not possible to determine the ultimate disposition of each of these proceedings and whether they will be resolved consistent with our beliefs, we expect that the outcome of such proceedings, individually or in the aggregate, will not have a material adverse effect on our financial position or results of operations. During the three-month period ended September 30, 2018, we settled a state tax matter for which we had previously accrued $114 million, with no material impact on our financial position or results of operations upon final settlement. Spectrum Reconfiguration Obligations In 2004, the FCC adopted a Report and Order that included new rules regarding interference in the 800 MHz band and a comprehensive plan to reconfigure the 800 MHz band. The Report and Order provides for the exchange of a portion of our 800 MHz FCC spectrum licenses, and requires us to fund the cost incurred by public safety systems and other incumbent licensees to reconfigure the 800 MHz spectrum band. Also, in exchange, we received licenses for 10 MHz of nationwide spectrum in the 1.9 GHz band. The minimum cash obligation was $2.8 billion under the Report and Order. We are, however, obligated to continue to pay the full amount of the costs relating to the reconfiguration plan, although those costs have exceeded $2.8 billion. As required under the terms of the Report and Order, a letter of credit has been secured to provide assurance that funds will be available to pay the relocation costs of the incumbent users of the 800 MHz spectrum. The letter of credit was initially $2.5 billion, but has been reduced during the course of the proceeding to $78 million as of December 31, 2018. Since the inception of the program, we have incurred payments of approximately $3.6 billion directly attributable to our performance under the Report and Order, including $35 million during the nine-month period ended December 31, 2018. When incurred, substantially all costs are accounted for as additions to FCC licenses with the remainder as property, plant and equipment. Based on our expenses to date and on third party administrator's audits, we have exceeded $2.8 billion minimum cash obligation required by the FCC. On October 12, 2017, the FCC released a Declaratory Ruling that we have met the minimum cash obligation under the Report and Order and concluded that Sprint will not be required to make any payments to the U.S. Treasury. Completion of the 800 MHz band reconfiguration was initially required by June 26, 2008 and public safety reconfiguration is nearly complete across the country with the exception of the States of California and Texas. These areas, however, are nearly complete. The FCC continues to grant the remaining 800 MHz public safety licensees additional time to complete their band reconfigurations which, in turn, delays our access to our 800 MHz replacement channels in these areas. In the non-border areas of these states where band reconfiguration is complete, Sprint has received its replacement spectrum in the 800 MHz band and Sprint is deploying 3G CDMA and 4G LTE on this spectrum in combination with its spectrum in the 1.9 GHz and 2.5 GHz bands.

Commitments and Contingencies

Litigation, Claims and Assessments

In March 2009, a stockholder brought suit, Bennett v. Sprint Nextel Corp., in the U.S. District Court for the District of Kansas, alleging that Sprint Communications and three of its former officers violated Section 10(b) of the Exchange Act and Rule 10b-5 by failing adequately to disclose certain alleged operational difficulties subsequent to the Sprint-Nextel merger, and by purportedly issuing false and misleading statements regarding the write-down of goodwill. The district court granted final approval of a settlement in August 2015, which did not have a material impact to our financial statements. Five stockholder derivative suits related to this 2009 stockholder suit were filed against Sprint Communications and certain of its present and/or former officers and directors. The first, Murphy v. Forsee, was filed in state court in Kansas on April 8, 2009, was removed to federal court, and was stayed by the court pending resolution of the motion to dismiss the Bennett case; the second, Randolph v. Forsee, was filed on July 15, 2010 in state court in Kansas, was removed to federal court, and was remanded back to state court; the third, Ross-Williams v. Bennett, et al., was filed in state court in Kansas on February 1, 2011; the fourth, Price v. Forsee, et al., was filed in state court in Kansas on April 15, 2011; and the fifth, Hartleib v. Forsee, et al., was filed in federal court in Kansas on July 14, 2011. These cases were essentially stayed while the Bennett case was pending, and we have reached an agreement in principle to settle the matters, by agreeing to some governance provisions and by paying plaintiffs' attorneys fees in an immaterial amount. The court approved the settlement but reduced the plaintiffs' attorneys fees. On April 27, 2018, the court of appeals for the state of Kansas affirmed the settlement ruling. On May 30, 2018, plaintiffs filed a Petition for Review with the Supreme Court of Kansas. On November 21, 2018, the Supreme Court of Kansas denied the Petition for Review, which concluded the case.

On April 19, 2012, the New York Attorney General filed a complaint alleging that Sprint Communications had fraudulently failed to collect and pay more than $100 million in New York sales taxes on receipts from its sale of wireless telephone services since July 2005. The complaint also sought recovery of triple damages under the State False Claims Act, as well as penalties and interest. Sprint Communications moved to dismiss the complaint on June 14, 2012. On July 1, 2013, the court entered an order denying the motion to dismiss in large part, although it did dismiss certain counts or parts of certain counts. Sprint Communications appealed that order and the intermediate appellate court affirmed the order of the trial court. On October 20, 2015, the Court of Appeals of New York affirmed the decision of the appellate court that the tax statute required us to collect and remit the disputed taxes. Our petition for certiorari to the U.S. Supreme Court on grounds of federal preemption was denied. We previously paid the principal amount of tax at issue, under protest, while the suit was pending. On December 21, 2018, Sprint Communications and the State of New York settled the dispute, as well as an unrelated tax matter. As a result, the Company recognized an additional $50 million of litigation expense during the three-month period ended December 31, 2018.

Eight related stockholder derivative suits have been filed against Sprint Communications and certain of its current and former officers and directors. Each suit alleges generally that the individual defendants breached their fiduciary duties to Sprint Communications and its stockholders by allegedly permitting, and failing to disclose, the actions alleged in the suit filed by the New York Attorney General. One suit, filed by the Louisiana Municipal Police Employees Retirement System, was dismissed by a federal court. Two suits were filed in state court in Johnson County, Kansas and one of those suits was dismissed as premature; and five suits are pending in federal court in Kansas. The remaining Kansas suits have been stayed pending resolution of the Attorney General's suit. We do not expect the resolution of these matters to have a material adverse effect on our financial position or results of operations.

On October 9, 2018, October 18, 2018, and October 24, 2018, three purported stockholders of Sprint commenced actions, captioned Klein v. Sprint Corporation et al., Muehlgay v. Sprint Corporation et al., and Binns Blount v. Sprint Corporation et al., in the United States District Court for the District of Delaware. The complaints name Sprint and the members of the Sprint board of directors as defendants. The complaints asserted claims under Section 14(a) and Section 20(a) of the Exchange Act challenging the adequacy of the disclosures relating to the proposed merger transactions with T-Mobile made in the associated joint consent solicitation statement/prospectus. The complaints sought, among other relief, an injunction preventing the parties from consummating the merger transactions, damages in the event the merger transactions are consummated, and the award of attorneys’ fees. On October 29, 2018, the plaintiff in the Binns Blount action filed a notice voluntarily dismissing their complaint without prejudice. On December 27, 2018, the Klein case was dismissed. On January 4, 2019, the Muehlgay case was dismissed.

Sprint is currently involved in numerous court actions alleging that Sprint is infringing various patents. Most of these cases effectively seek only monetary damages. A small number of these cases are brought by companies that sell products and seek injunctive relief as well. These cases have progressed to various degrees and a small number may go to trial if they are not otherwise resolved. Adverse resolution of these cases could require us to pay significant damages, cease certain activities, or cease selling the relevant products and services. In many circumstances, we would be indemnified for monetary losses that we incur with respect to the actions of our suppliers or service providers. We do not expect the resolution of these cases to have a material adverse effect on our financial position or results of operations.

In October 2013, the FCC Enforcement Bureau began to issue notices of apparent liability (NALs) to other Lifeline providers, imposing fines for intracarrier duplicate accounts identified by the government during its audit function. Those audits also identified a small percentage of potentially duplicative intracarrier accounts related to our Assurance Wireless^® business. No NAL has yet been issued with respect to Sprint and we do not know if one will be issued. Further, we are not able to reasonably estimate the amount of any claim for penalties that might be asserted. However, based on the information currently available, if a claim is asserted by the FCC, Sprint does not believe that any amount ultimately paid would be material to the Company’s results of operations or financial position.

Various other suits, inquiries, proceedings and claims, either asserted or unasserted, including purported class actions typical for a large business enterprise and intellectual property matters, are possible or pending against us or our subsidiaries. If our interpretation of certain laws or regulations, including those related to various federal or state matters such as sales, use or property taxes, or other charges were found to be mistaken, it could result in payments by us. While it is not possible to determine the ultimate disposition of each of these proceedings and whether they will be resolved consistent with our beliefs, we expect that the outcome of such proceedings, individually or in the aggregate, will not have a material adverse effect on our financial position or results of operations. During the three-month period ended September 30, 2018, we settled a state tax matter for which we had previously accrued $114 million, with no material impact on our financial position or results of operations upon final settlement.

Spectrum Reconfiguration Obligations

In 2004, the FCC adopted a Report and Order that included new rules regarding interference in the 800 MHz band and a comprehensive plan to reconfigure the 800 MHz band. The Report and Order provides for the exchange of a portion of our 800 MHz FCC spectrum licenses, and requires us to fund the cost incurred by public safety systems and other incumbent licensees to reconfigure the 800 MHz spectrum band. Also, in exchange, we received licenses for 10 MHz of nationwide spectrum in the 1.9 GHz band.

The minimum cash obligation was $2.8 billion under the Report and Order. We are, however, obligated to continue to pay the full amount of the costs relating to the reconfiguration plan, although those costs have exceeded $2.8 billion. As required under the terms of the Report and Order, a letter of credit has been secured to provide assurance that funds will be available to pay the relocation costs of the incumbent users of the 800 MHz spectrum. The letter of credit was initially $2.5 billion, but has been reduced during the course of the proceeding to $78 million as of December 31, 2018. Since the inception of the program, we have incurred payments of approximately $3.6 billion directly attributable to our performance under the Report and Order, including $35 million during the nine-month period ended December 31, 2018. When incurred, substantially all costs are accounted for as additions to FCC licenses with the remainder as property, plant and equipment. Based on our expenses to date and on third party administrator's audits, we have exceeded $2.8 billion minimum cash obligation required by the FCC. On October 12, 2017, the FCC released a Declaratory Ruling that we have met the minimum cash obligation under the Report and Order and concluded that Sprint will not be required to make any payments to the U.S. Treasury.

Completion of the 800 MHz band reconfiguration was initially required by June 26, 2008 and public safety reconfiguration is nearly complete across the country with the exception of the States of California and Texas. These areas, however, are nearly complete. The FCC continues to grant the remaining 800 MHz public safety licensees additional time to complete their band reconfigurations which, in turn, delays our access to our 800 MHz replacement channels in these areas. In the non-border areas of these states where band reconfiguration is complete, Sprint has received its replacement spectrum in the 800 MHz band and Sprint is deploying 3G CDMA and 4G LTE on this spectrum in combination with its spectrum in the 1.9 GHz and 2.5 GHz bands.