Business Segment Reporting - Financial Information (Details) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended
	Jul. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Jul. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment					4
Revenues:
Service related, net		$ 259
Net gain on mortgage loans held for sale		83
Total revenues		342
Total Expenses		275
Other income (expenses)
Interest income		90
Interest expense		(122)
Other		6
Total other income (expenses), net		(26)
Income before income tax expense (benefit)		41
Depreciation and amortization for property and equipment and intangible assets		15
Total assets		17,728			$ 17,728
Predecessor
Revenues:
Service related, net	$ 120		$ 252	$ 901		$ 748
Net gain on mortgage loans held for sale	44		154	295		465
Total revenues	164		406	1,196		1,213
Total Expenses	242		368	945		1,104
Other income (expenses)
Interest income	48		159	333		437
Interest expense	(53)		(183)	(388)		(564)
Other	0		(2)	6		4
Total other income (expenses), net	(5)		(26)	(49)		(123)
Income before income tax expense (benefit)	(83)		12	202		(14)
Depreciation and amortization for property and equipment and intangible assets	4		15	33		44
Total assets	17,026		18,004	17,026		18,004	$ 18,036
Operating Segments
Revenues:
Service related, net		259
Net gain on mortgage loans held for sale		83
Total revenues		342
Total Expenses		241
Other income (expenses)
Interest income		88
Interest expense		(85)
Other		6
Total other income (expenses), net		9
Income before income tax expense (benefit)		110
Depreciation and amortization for property and equipment and intangible assets		8
Total assets		15,983			15,983
Operating Segments | Predecessor
Revenues:
Service related, net	120		252	900		747
Net gain on mortgage loans held for sale	44		154	295		465
Total revenues	164		406	1,195		1,212
Total Expenses	179		345	842		1,032
Other income (expenses)
Interest income	47		157	326		425
Interest expense	(41)		(145)	(305)		(448)
Other	0		(2)	8		6
Total other income (expenses), net	6		10	29		(17)
Income before income tax expense (benefit)	(9)		71	382		163
Depreciation and amortization for property and equipment and intangible assets	4		12	29		34
Total assets	16,113		17,225	16,113		17,225
Operating Segments | Servicing Segment
Revenues:
Service related, net		183
Net gain on mortgage loans held for sale		0
Total revenues		183
Total Expenses		104
Other income (expenses)
Interest income		78
Interest expense		(74)
Other		5
Total other income (expenses), net		9
Income before income tax expense (benefit)		88
Depreciation and amortization for property and equipment and intangible assets		4
Total assets		14,166			14,166
Operating Segments | Servicing Segment | Predecessor
Revenues:
Service related, net	97		191	740		537
Net gain on mortgage loans held for sale	0		0	0		0
Total revenues	97		191	740		537
Total Expenses	126		185	474		513
Other income (expenses)
Interest income	41		143	288		386
Interest expense	(35)		(132)	(268)		(409)
Other	0		(2)	(1)		(2)
Total other income (expenses), net	6		9	19		(25)
Income before income tax expense (benefit)	(23)		15	285		(1)
Depreciation and amortization for property and equipment and intangible assets	2		6	15		16
Total assets	14,578		15,147	14,578		15,147
Operating Segments | Originations Segment
Revenues:
Service related, net		10
Net gain on mortgage loans held for sale		76
Total revenues		86
Total Expenses		66
Other income (expenses)
Interest income		10
Interest expense		(10)
Other		1
Total other income (expenses), net		1
Income before income tax expense (benefit)		21
Depreciation and amortization for property and equipment and intangible assets		2
Total assets		4,892			4,892
Operating Segments | Originations Segment | Predecessor
Revenues:
Service related, net	4		16	36		47
Net gain on mortgage loans held for sale	41		134	270		402
Total revenues	45		150	306		449
Total Expenses	34		106	245		326
Other income (expenses)
Interest income	6		14	38		39
Interest expense	(6)		(13)	(37)		(39)
Other	0		0	0		0
Total other income (expenses), net	0		1	1		0
Income before income tax expense (benefit)	11		45	62		123
Depreciation and amortization for property and equipment and intangible assets	1		3	7		8
Total assets	4,701		4,644	4,701		4,644
Operating Segments | Xome
Revenues:
Service related, net		73
Net gain on mortgage loans held for sale		0
Total revenues		73
Total Expenses		71
Other income (expenses)
Interest income		0
Interest expense		(1)
Other		0
Total other income (expenses), net		(1)
Income before income tax expense (benefit)		1
Depreciation and amortization for property and equipment and intangible assets		2
Total assets		457			457
Operating Segments | Xome | Predecessor
Revenues:
Service related, net	22		65	149		226
Net gain on mortgage loans held for sale	0		0	0		0
Total revenues	22		65	149		226
Total Expenses	19		54	123		193
Other income (expenses)
Interest income	0		0	0		0
Interest expense	0		0	0		0
Other	0		0	9		8
Total other income (expenses), net	0		0	9		8
Income before income tax expense (benefit)	3		11	35		41
Depreciation and amortization for property and equipment and intangible assets	1		3	7		10
Total assets	425		382	425		382
Eliminations
Revenues:
Service related, net		(7)
Net gain on mortgage loans held for sale		7
Total revenues		0
Total Expenses		0
Other income (expenses)
Interest income		0
Interest expense		0
Other		0
Total other income (expenses), net		0
Income before income tax expense (benefit)		0
Depreciation and amortization for property and equipment and intangible assets		0
Total assets		(3,532)			(3,532)
Eliminations | Predecessor
Revenues:
Service related, net	(3)		(20)	(25)		(63)
Net gain on mortgage loans held for sale	3		20	25		63
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
Income before income tax expense (benefit)	0		0	0		0
Depreciation and amortization for property and equipment and intangible assets	0		0	0		0
Total assets	(3,591)		(2,948)	(3,591)		(2,948)
Corporate and Other
Revenues:
Service related, net		0
Net gain on mortgage loans held for sale		0
Total revenues		0
Total Expenses		34
Other income (expenses)
Interest income		2
Interest expense		(37)
Other		0
Total other income (expenses), net		(35)
Income before income tax expense (benefit)		(69)
Depreciation and amortization for property and equipment and intangible assets		7
Total assets		$ 1,745			$ 1,745
Corporate and Other | Predecessor
Revenues:
Service related, net	0		0	1		1
Net gain on mortgage loans held for sale	0		0	0		0
Total revenues	0		0	1		1
Total Expenses	63		23	103		72
Other income (expenses)
Interest income	1		2	7		12
Interest expense	(12)		(38)	(83)		(116)
Other	0		0	(2)		(2)
Total other income (expenses), net	(11)		(36)	(78)		(106)
Income before income tax expense (benefit)	(74)		(59)	(180)		(177)
Depreciation and amortization for property and equipment and intangible assets	0		3	4		10
Total assets	$ 913		$ 779	$ 913		$ 779