Discontinued Operations and Disposal Groups (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 01, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets of discontinued operations	$ 0	$ 5,347
Liabilities of discontinued operations	0	5,203
Net (loss) income from discontinued operations	(12)	(2)	$ 16
Discontinued Operation, Loan Asset Retained	55
Discontinued Operation, Loan Liability Retained	39
Discontinued Operations, Held-for-sale or Disposed of by Sale | Champion Mortgage
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted cash		83
Reverse mortgage interests, net		5,253
Other		11
Assets of discontinued operations		5,347
Advances and warehouse facilities, net		505
Payables and other liabilities		233
Mortgage servicing liabilities		41
Other nonrecourse debt, net		4,424
Liabilities of discontinued operations		5,203
Revenue - service related, net	26	44	80
Salaries, wages and benefits expense	(30)	(41)	(64)
General and administrative expense	21	(8)	(73)
Interest income	137	176	314
Interest expense	(105)	(174)	(236)
Loss on classification as discontinued operations	(65)	0	0
(Loss) income from discontinued operations before income tax (benefit) expense	(16)	(3)	21
Less: Income tax (benefit) expense	(4)	(1)	5
Net (loss) income from discontinued operations	(12)	$ (2)	$ 16
Disposal Group, Including Discontinued Operation, Consideration				$ 1,640
Disposal Group, Discontinued Operation, Transaction Cost	$ 4