Document and Entity Information - shares	6 Months Ended
	Jul. 03, 2015	Jul. 24, 2015
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	true
Document Period End Date	Jul. 03, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Trading Symbol	LDOS
Entity Registrant Name	Leidos Holdings, Inc.
Entity Central Index Key	0001336920
Current Fiscal Year End Date	--01-02
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		72,063,425
Amendment Description	Explanatory Note to Amendment No.1 The sole purpose of this Amendment No. 1 on Form 10-Q/A is to amend the certification filed as Exhibit 32.1 to our Form 10-Q for the quarter ended July 3, 2015, filed on August 5, 2015 (the “Original Filing”) to correct the inadvertent omission of the conformed signature of the Chief Executive Officer on the certification. The certification was fully executed on August 5, 2015 and was in our possession at the time of the Original Filing. Other than as set forth above, this Amendment No. 1 does not modify or update disclosures in the Original Filing. Accordingly, this Amendment No. 1 does not reflect events that may have occurred after the Original Filing or modify or update any related or other disclosures. Explanatory Note This Quarterly Report on Form 10-Q is a combined report being filed by Leidos Holdings, Inc. ("Leidos") and Leidos, Inc. Leidos is a holding company and Leidos, Inc. is a direct, 100%-owned subsidiary of Leidos. Each of Leidos and Leidos, Inc. is filing on its own behalf all of the information contained in this report that relates to such company. Where information or an explanation is provided that is substantially the same for each company, such information or explanation has been combined in this report. Where information or an explanation is not substantially the same for each company, separate information and explanation has been provided. In addition, separate condensed consolidated financial statements for each company, along with combined notes to the condensed consolidated financial statements, are included in this report. Unless indicated otherwise, references in this report to the “Company,” “we,” “us,” and “our” refer collectively to Leidos Holdings, Inc., Leidos, Inc., and its consolidated subsidiaries. In March 2015, the Company announced a change to its fiscal year end from the Friday nearest the end of January to the Friday nearest the end of December. The year-to-date results are for the six months ended July 3, 2015, which includes the last month of the previous fiscal year ended January 30, 2015, whereas the results for the prior period are for the six months ended August 1, 2014. The quarterly results are for the three months ended July 3, 2015, whereas the results for the prior period are for the three months ended August 1, 2014.
Leidos, Inc.
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	true
Document Period End Date	Jul. 03, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Entity Registrant Name	Leidos, Inc.
Entity Central Index Key	0000353394
Current Fiscal Year End Date	--01-02
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		5,000
Amendment Description	Explanatory Note to Amendment No.1 The sole purpose of this Amendment No. 1 on Form 10-Q/A is to amend the certification filed as Exhibit 32.1 to our Form 10-Q for the quarter ended July 3, 2015, filed on August 5, 2015 (the “Original Filing”) to correct the inadvertent omission of the conformed signature of the Chief Executive Officer on the certification. The certification was fully executed on August 5, 2015 and was in our possession at the time of the Original Filing. Other than as set forth above, this Amendment No. 1 does not modify or update disclosures in the Original Filing. Accordingly, this Amendment No. 1 does not reflect events that may have occurred after the Original Filing or modify or update any related or other disclosures. Explanatory Note This Quarterly Report on Form 10-Q is a combined report being filed by Leidos Holdings, Inc. ("Leidos") and Leidos, Inc. Leidos is a holding company and Leidos, Inc. is a direct, 100%-owned subsidiary of Leidos. Each of Leidos and Leidos, Inc. is filing on its own behalf all of the information contained in this report that relates to such company. Where information or an explanation is provided that is substantially the same for each company, such information or explanation has been combined in this report. Where information or an explanation is not substantially the same for each company, separate information and explanation has been provided. In addition, separate condensed consolidated financial statements for each company, along with combined notes to the condensed consolidated financial statements, are included in this report. Unless indicated otherwise, references in this report to the “Company,” “we,” “us,” and “our” refer collectively to Leidos Holdings, Inc., Leidos, Inc., and its consolidated subsidiaries. In March 2015, the Company announced a change to its fiscal year end from the Friday nearest the end of January to the Friday nearest the end of December. The year-to-date results are for the six months ended July 3, 2015, which includes the last month of the previous fiscal year ended January 30, 2015, whereas the results for the prior period are for the six months ended August 1, 2014. The quarterly results are for the three months ended July 3, 2015, whereas the results for the prior period are for the three months ended August 1, 2014.