Discontinued Operations and Disposal Groups (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets of discontinues operations	$ 4,935		$ 4,935		$ 5,347
Liabilities of discontinued operations	4,790		4,790		5,203
Net income (loss) from discontinued operations	12	$ (4)	14	$ (16)
Discontinued Operation, Loan Asset Retained	112		112
Discontinued Operation, Loan Liability Retained	88		88
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] | Champion Mortgage [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted cash	77		77		83
Reverse mortgage interests, net	4,910		4,910		5,253
Other	9		9		11
Loss recognized on classification as discontinued operations	(61)		(61)		0
Total assets of discontinues operations	4,935		4,935		5,347
Advances and warehouse facilities, net	525		525		505
Payables and other liabilities	224		224		233
Mortgage servicing liabilities	42		42		41
Other nonrecourse debt, net	3,999		3,999		4,424
Liabilities of discontinued operations	4,790		4,790		$ 5,203
Revenue - service related, net	1	12	9	26
Salaries, wages and benefits expense	(8)	(10)	(16)	(22)
General and administrative expense	71	(10)	64	(18)
Interest income	43	53	87	96
Interest expense	(30)	(50)	(64)	(103)
Loss on classification as discontinued operations	(61)	0	(61)	0
Income (loss) from discontinued operations before income tax expense (benefit)	16	(5)	19	(21)
Less: Income tax expense (benefit)	4	(1)	5	(5)
Net income (loss) from discontinued operations	$ 12	$ (4)	$ 14	$ (16)