Loans Receivable, Net (Details - Allowance) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses, Additional Information [Line Items]
Allowance for loan losses, beginning of period	$ 37	$ 74	$ 221
Provision (benefit) for loan losses	(51)	(86)	(168)
Charge-offs	(3)	(4)	(13)
Recoveries	34	53	34
Net (charge-offs) recoveries	31	49	21
Allowance for loan losses, end of period	17	37	74
Recovery from the sale of previously charged-off loans	3	15
Provision (benefit) for loan losses	$ (51)	$ (86)	(168)
Allowance as a percentage of total loans receivable	1.10%	1.70%
One- To Four-Family [Member]
Financing Receivable, Allowance for Credit Losses, Additional Information [Line Items]
Allowance for loan losses, beginning of period	$ 9	$ 24	45
Provision (benefit) for loan losses	(9)	(22)	(29)
Charge-offs	0	0	0
Recoveries	6	7	8
Net (charge-offs) recoveries	6	7	8
Allowance for loan losses, end of period	6	9	24
Provision (benefit) for loan losses	$ (9)	$ (22)	(29)
Allowance as a percentage of total loans receivable	0.70%	0.80%
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses, Additional Information [Line Items]
Allowance for loan losses, beginning of period	$ 26	$ 46	171
Provision (benefit) for loan losses	(41)	(63)	(141)
Charge-offs	0	0	(7)
Recoveries	26	43	23
Net (charge-offs) recoveries	26	43	16
Allowance for loan losses, end of period	11	26	46
Provision (benefit) for loan losses	$ (41)	$ (63)	(141)
Allowance as a percentage of total loans receivable	1.70%	3.10%
Consumer and other [Member]
Financing Receivable, Allowance for Credit Losses, Additional Information [Line Items]
Allowance for loan losses, beginning of period	$ 2	$ 4	5
Provision (benefit) for loan losses	(1)	(1)	2
Charge-offs	(3)	(4)	(6)
Recoveries	2	3	3
Net (charge-offs) recoveries	(1)	(1)	(3)
Allowance for loan losses, end of period	0	2	4
Provision (benefit) for loan losses	(1)	$ (1)	$ 2
Allowance as a percentage of total loans receivable		1.00%
Held-for-investment [Member]
Financing Receivable, Allowance for Credit Losses, Additional Information [Line Items]
Increase (Decrease) in Finance Receivables	$ (500)