Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Shares Amount	Total Nationstar Stockholders’ Equity and Mr. Cooper Stockholders’ Equity, respectively	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2016			97,497
Beginning balance at Dec. 31, 2016	$ 1,683		$ 1	$ 1,122	$ 701	$ (147)	$ 1,677	$ 6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)			231
Shares issued / (surrendered) under incentive compensation plan	(4)			(3)		(1)	(4)
Share-based compensation	17			17			17
Dividends to non-controlling interests	(5)			(5)			(5)
Net income	31				30		30	1
Ending balance at Dec. 31, 2017	1,722		$ 1	1,131	731	(148)	1,715	7
Ending balance (in shares) at Dec. 31, 2017			97,728
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)			450
Shares issued / (surrendered) under incentive compensation plan	(9)			(6)		(3)	(9)
Share-based compensation	17			17			17
Dividends to non-controlling interests	(1)			5			5	(6)
Net income	154				154		154
Ending balance at Jul. 31, 2018	1,883		$ 1	1,147	885	(151)	1,882	1
Ending balance (in shares) at Jul. 31, 2018			98,178
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-controlling interests acquired	3							3
Shares issued / (surrendered) under incentive compensation plan (in shares)			15
Shares issued / (surrendered) under incentive compensation plan	0
Share-based compensation	2			2			2
Net income	884				884		884
Ending balance at Dec. 31, 2018	1,945	$ 0	$ 1	1,093	848	0	1,942	3
Ending balance (in shares) at Dec. 31, 2018		1,000	90,821
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued / (surrendered) under incentive compensation plan (in shares)			297
Shares issued / (surrendered) under incentive compensation plan	(2)			(2)			(2)
Share-based compensation	18			18			18
Net income	270				274		274	(4)
Ending balance at Dec. 31, 2019	$ 2,231	$ 0	$ 1	$ 1,109	$ 1,122	$ 0	$ 2,232	$ (1)
Ending balance (in shares) at Dec. 31, 2019		1,000	91,118