Guarantor Financial Statement Information - Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 181	$ 242
Restricted cash	339	319
Mortgage servicing rights	3,488	3,676
Advances and other receivables, net	1,147	1,194
Reverse mortgage interests, net	7,489	7,934
Mortgage loans held for sale at fair value	2,170	1,631
Mortgage loans held for investment at fair value	118	119
Property and equipment, net	112	96
Deferred tax asset, net	1,024	967
Other assets	1,578	795
Investment in subsidiaries	0	0
Total assets	17,646	16,973
Liabilities and Stockholders’ Equity
Unsecured senior notes, net	2,461	2,459
Advance facilities	578	595
Warehouse facilities	3,050	2,349
Payables and other liabilities	1,975	1,543
MSR related liabilities - nonrecourse at fair value	1,343	1,216
Mortgage servicing liabilities	90	71
Other nonrecourse debt, net	6,388	6,795
Payables to affiliates	0	0
Total liabilities	15,885	15,028
Total stockholders' equity	1,761	1,945
Total liabilities and stockholders’ equity	17,646	16,973
Eliminations
Assets
Cash and cash equivalents	0	0
Restricted cash	0	0
Mortgage servicing rights	0	0
Advances and other receivables, net	0	0
Reverse mortgage interests, net	0	0
Mortgage loans held for sale at fair value	0	0
Mortgage loans held for investment at fair value	0	0
Property and equipment, net	0	0
Deferred tax asset, net	0	0
Other assets	(662)	(688)
Investment in subsidiaries	(3,211)	(3,421)
Total assets	(3,873)	(4,109)
Liabilities and Stockholders’ Equity
Unsecured senior notes, net	0	0
Advance facilities	0	0
Warehouse facilities	0	0
Payables and other liabilities	0	0
MSR related liabilities - nonrecourse at fair value	0	0
Mortgage servicing liabilities	0	0
Other nonrecourse debt, net	0	0
Payables to affiliates	(662)	(688)
Total liabilities	(662)	(688)
Total stockholders' equity	(3,211)	(3,421)
Total liabilities and stockholders’ equity	(3,873)	(4,109)
Mr. Cooper | Reportable entities
Assets
Cash and cash equivalents	0	0
Restricted cash	0	0
Mortgage servicing rights	0	0
Advances and other receivables, net	0	0
Reverse mortgage interests, net	0	0
Mortgage loans held for sale at fair value	0	0
Mortgage loans held for investment at fair value	0	0
Property and equipment, net	0	0
Deferred tax asset, net	984	973
Other assets	0	0
Investment in subsidiaries	2,602	2,820
Total assets	3,586	3,793
Liabilities and Stockholders’ Equity
Unsecured senior notes, net	1,662	1,660
Advance facilities	0	0
Warehouse facilities	0	0
Payables and other liabilities	22	49
MSR related liabilities - nonrecourse at fair value	0	0
Mortgage servicing liabilities	0	0
Other nonrecourse debt, net	0	0
Payables to affiliates	141	139
Total liabilities	1,825	1,848
Total stockholders' equity	1,761	1,945
Total liabilities and stockholders’ equity	3,586	3,793
Issuer | Reportable entities
Assets
Cash and cash equivalents	151	193
Restricted cash	191	186
Mortgage servicing rights	3,460	3,644
Advances and other receivables, net	1,147	1,194
Reverse mortgage interests, net	6,427	6,770
Mortgage loans held for sale at fair value	2,170	1,631
Mortgage loans held for investment at fair value	1	1
Property and equipment, net	99	84
Deferred tax asset, net	38	0
Other assets	1,435	660
Investment in subsidiaries	609	601
Total assets	15,728	14,964
Liabilities and Stockholders’ Equity
Unsecured senior notes, net	799	799
Advance facilities	89	90
Warehouse facilities	3,050	2,349
Payables and other liabilities	1,870	1,413
MSR related liabilities - nonrecourse at fair value	1,326	1,197
Mortgage servicing liabilities	90	71
Other nonrecourse debt, net	5,381	5,676
Payables to affiliates	521	549
Total liabilities	13,126	12,144
Total stockholders' equity	2,602	2,820
Total liabilities and stockholders’ equity	15,728	14,964
Guarantor (Subsidiaries of Issuer) | Reportable entities
Assets
Cash and cash equivalents	1	1
Restricted cash	0	0
Mortgage servicing rights	0	0
Advances and other receivables, net	0	0
Reverse mortgage interests, net	0	0
Mortgage loans held for sale at fair value	0	0
Mortgage loans held for investment at fair value	0	0
Property and equipment, net	0	0
Deferred tax asset, net	0	0
Other assets	204	202
Investment in subsidiaries	0	0
Total assets	205	203
Liabilities and Stockholders’ Equity
Unsecured senior notes, net	0	0
Advance facilities	0	0
Warehouse facilities	0	0
Payables and other liabilities	2	1
MSR related liabilities - nonrecourse at fair value	0	0
Mortgage servicing liabilities	0	0
Other nonrecourse debt, net	0	0
Payables to affiliates	0	0
Total liabilities	2	1
Total stockholders' equity	203	202
Total liabilities and stockholders’ equity	205	203
Non-Guarantor (Subsidiaries of Issuer) | Reportable entities
Assets
Cash and cash equivalents	29	48
Restricted cash	148	133
Mortgage servicing rights	28	32
Advances and other receivables, net	0	0
Reverse mortgage interests, net	1,062	1,164
Mortgage loans held for sale at fair value	0	0
Mortgage loans held for investment at fair value	117	118
Property and equipment, net	13	12
Deferred tax asset, net	2	(6)
Other assets	601	621
Investment in subsidiaries	0	0
Total assets	2,000	2,122
Liabilities and Stockholders’ Equity
Unsecured senior notes, net	0	0
Advance facilities	489	505
Warehouse facilities	0	0
Payables and other liabilities	81	80
MSR related liabilities - nonrecourse at fair value	17	19
Mortgage servicing liabilities	0	0
Other nonrecourse debt, net	1,007	1,119
Payables to affiliates	0	0
Total liabilities	1,594	1,723
Total stockholders' equity	406	399
Total liabilities and stockholders’ equity	$ 2,000	$ 2,122