Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Treasury Shares Amount	Total Mr. Cooper Stockholders’ Equity	Total Mr. Cooper Stockholders’ Equity Cumulative Effect, Period of Adoption, Adjustment	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2018			1,000	90,821
Beginning balance at Dec. 31, 2018	$ 1,945		$ 0	$ 1	$ 1,093	$ 848		$ 0	$ 1,942		$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)				297
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(2)				(2)				(2)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	18				18				18
Net income	270					274			274		(4)
Ending balance (in shares) at Dec. 31, 2019			1,000	91,118
Ending balance at Dec. 31, 2019	2,231		$ 0	$ 1	1,109	1,122		0	2,232		(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)				923
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(5)				(5)				(5)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	22				22				22
Repurchase of common stock (in shares)				2,584
Repurchase of common stock	(58)							(58)	(58)
Net income	307					305			305		2
Ending balance (in shares) at Dec. 31, 2020			1,000	89,457
Ending balance at Dec. 31, 2020	2,504	$ 7	$ 0	$ 1	1,126	1,434	$ 7	(58)	2,503	$ 7	1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)				1,244
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(20)				(20)				(20)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	29				29				29
Repurchase of common stock (in shares)				16,924
Repurchase of common stock	(572)							(572)	(572)
Stock Repurchased and Retired During Period, Shares			(1,000)
Stock Repurchased and Retired During Period, Value	(28)				(19)	(9)			(28)
Net income	1,454					1,454			1,454		0
Ending balance (in shares) at Dec. 31, 2021			0	73,777
Ending balance at Dec. 31, 2021	$ 3,367		$ 0	$ 1	$ 1,116	$ 2,879		$ (630)	$ 3,366		$ 1