Document and Entity Information - shares	9 Months Ended
	Dec. 31, 2017	Jan. 30, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Trading Symbol	S
Entity Registrant Name	SPRINT CORP
Entity Central Index Key	0000101830
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		4,003,046,276