Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net loss attributable to Mr. Cooper	$ (168)	$ (186)
Less: Undistributed earnings attributable to participating stockholders	0	0
Net loss attributable to common stockholders	$ (168)	$ (186)
Net loss per common share attributable to Mr. Cooper:
Basic (in dollars per share)	$ (1.84)	$ (2.05)
Diluted (in dollars per share)	$ (1.84)	$ (2.05)
Weighted average shares of common stock outstanding (in thousands):
Basic (in shares)	91,385	90,828
Dilutive effect of stock awards (in shares)	0	0
Dilutive effect of participating securities (in shares)	0	0
Diluted (in shares)	91,385	90,828