Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 25, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	Mr. Cooper Group Inc.
Entity Central Index Key	0000933136
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Emerging Growth Company	false
Small Business Entity	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		91,087,252
Entity Shell Company	false