Business Segment Reporting - Financial Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) segment	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			4
Revenues:
Service related, net	$ 137	$ 317	$ 221	$ 781
Net gain on mortgage loans held for sale	262	127	428	251
Total revenues	399	444	649	1,032
Total Expenses	492	339	935	703
Other income (expenses)
Interest income	162	140	296	285
Interest expense	(187)	(164)	(376)	(335)
Other	1	(2)	16	6
Total other income (expenses), net	(24)	(26)	(64)	(44)
(Loss) income before income tax (benefit) expense	(117)	79	(350)	285
Depreciation and amortization for property and equipment and intangible assets	24	14	45	29
Total assets	18,405	17,190	18,405	17,190	$ 16,973
Servicing Segment
Revenues:
Net gain on mortgage loans held for sale	18	11	53	22
Operating Segments
Revenues:
Service related, net	137	316	221	780
Net gain on mortgage loans held for sale	262	127	428	251
Total revenues	399	443	649	1,031
Total Expenses	435	320	833	663
Other income (expenses)
Interest income	159	138	291	279
Interest expense	(134)	(131)	(266)	(264)
Other	1	0	16	8
Total other income (expenses), net	26	7	41	23
(Loss) income before income tax (benefit) expense	(10)	130	(143)	391
Depreciation and amortization for property and equipment and intangible assets	13	12	24	25
Total assets	16,090	16,319	16,090	16,319
Operating Segments | Servicing Segment
Revenues:
Service related, net	27	248	35	643
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	27	248	35	643
Total Expenses	189	166	384	348
Other income (expenses)
Interest income	136	121	251	247
Interest expense	(109)	(115)	(223)	(233)
Other	0	0	0	(1)
Total other income (expenses), net	27	6	28	13
(Loss) income before income tax (benefit) expense	(135)	88	(321)	308
Depreciation and amortization for property and equipment and intangible assets	4	6	8	13
Total assets	12,806	14,640	12,806	14,640
Operating Segments | Originations Segment
Revenues:
Service related, net	20	17	35	32
Net gain on mortgage loans held for sale	244	116	375	229
Total revenues	264	133	410	261
Total Expenses	145	102	249	211
Other income (expenses)
Interest income	23	17	40	32
Interest expense	(25)	(16)	(43)	(31)
Other	1	0	5	0
Total other income (expenses), net	(1)	1	2	1
(Loss) income before income tax (benefit) expense	118	32	163	51
Depreciation and amortization for property and equipment and intangible assets	6	3	9	6
Total assets	7,478	4,794	7,478	4,794
Operating Segments | Xome
Revenues:
Service related, net	108	62	204	127
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	108	62	204	127
Total Expenses	101	52	200	104
Other income (expenses)
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other	0	0	11	9
Total other income (expenses), net	0	0	11	9
(Loss) income before income tax (benefit) expense	7	10	15	32
Depreciation and amortization for property and equipment and intangible assets	3	3	7	6
Total assets	493	423	493	423
Eliminations
Revenues:
Service related, net	(18)	(11)	(53)	(22)
Net gain on mortgage loans held for sale	18	11	53	22
Total revenues	0	0	0	0
Total Expenses	0	0	0	0
Other income (expenses)
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other	0	0	0	0
Total other income (expenses), net	0	0	0	0
(Loss) income before income tax (benefit) expense	0	0	0	0
Depreciation and amortization for property and equipment and intangible assets	0	0	0	0
Total assets	(4,687)	(3,538)	(4,687)	(3,538)
Corporate/Other
Revenues:
Service related, net	0	1	0	1
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	0	1	0	1
Total Expenses	57	19	102	40
Other income (expenses)
Interest income	3	2	5	6
Interest expense	(53)	(33)	(110)	(71)
Other	0	(2)	0	(2)
Total other income (expenses), net	(50)	(33)	(105)	(67)
(Loss) income before income tax (benefit) expense	(107)	(51)	(207)	(106)
Depreciation and amortization for property and equipment and intangible assets	11	2	21	4
Total assets	$ 2,315	$ 871	$ 2,315	$ 871