Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Total Mr. Cooper Stockholders’ Equity	Non-controlling Interests	Treasury Share Amount
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders’ equity	$ 3,367	$ 1	$ 1,116	$ 2,879	$ 3,366	$ 1	$ (630)
Shares outstanding, beginning balance (in shares) at Dec. 31, 2021		73,777
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)		850
Shares issued / (surrendered) under incentive compensation plan	(21)		(39)		(21)		18
Share-based compensation	8		8		8
Repurchase of common stock (in shares)		(721)
Repurchase of common stock	(35)				(35)		(35)
Net income	658			658	658	0
Shares outstanding, ending balance (in shares) at Mar. 31, 2022		73,906
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders’ equity	3,977	$ 1	1,085	3,537	3,976	1	(647)
Total stockholders’ equity	4,057	$ 1	1,104	3,802	4,057	0	(850)
Shares outstanding, beginning balance (in shares) at Dec. 31, 2022		69,266
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)		870
Shares issued / (surrendered) under incentive compensation plan	(24)		(43)		(24)		19
Share-based compensation	5		5		5
Repurchase of common stock (in shares)		(2,083)
Repurchase of common stock	(89)				(89)		(89)
Net income	37			37	37	0
Shares outstanding, ending balance (in shares) at Mar. 31, 2023		68,053
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders’ equity	$ 3,986	$ 1	$ 1,066	$ 3,839	$ 3,986	$ 0	$ (920)