Loans Receivable, Net (Details - Credit Quality) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	$ 1,607	$ 2,132
Average Age, Financing Receivable	13 years 8 months 12 days	12 years 9 months 18 days
Greater Than 10% of Loans States Other than California and New York, Count	0	0
Greater Than 10% of Past Due Loans, States Other than California and New York, Count	0
Greater Than 10% of Impaired Loans, States Other than California and New York, Count	0
One- To Four-Family [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	$ 803	$ 1,071
Average estimated current LTV/CLTV	61.00%	66.00%
Average LTV/CLTV at loan origination	70.00%	70.00%
One- To Four-Family [Member] | FICO Score, Greater than 720 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	$ 462	$ 617
One- To Four-Family [Member] | FICO Score, 719 to 700 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	77	89
One- To Four-Family [Member] | FICO Score, 699 to 680 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	55	80
One- To Four-Family [Member] | FICO Score, 679 to 660 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	40	66
One- To Four-Family [Member] | FICO Score, 659 to 620 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	63	79
One- To Four-Family [Member] | FICO Score, Less than 620 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	106	140
One- To Four-Family [Member] | Debt-to-Value Ratio, Less than 80 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	661	823
One- To Four-Family [Member] | Debt-to-Value Ratio, 80 to 100 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	97	165
One- To Four-Family [Member] | LTV 100 to 120 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	26	45
One- To Four-Family [Member] | LTV Greater than 120 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	19	38
Home Equity [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	$ 635	$ 836
Average estimated current LTV/CLTV	76.00%	80.00%
Average LTV/CLTV at loan origination	82.00%	82.00%
Home Equity [Member] | FICO Score, Greater than 720 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	$ 333	$ 442
Home Equity [Member] | FICO Score, 719 to 700 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	61	78
Home Equity [Member] | FICO Score, 699 to 680 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	54	70
Home Equity [Member] | FICO Score, 679 to 660 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	43	56
Home Equity [Member] | FICO Score, 659 to 620 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	59	80
Home Equity [Member] | FICO Score, Less than 620 [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	85	110
Home Equity [Member] | Debt-to-Value Ratio, Less than 80 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	377	454
Home Equity [Member] | Debt-to-Value Ratio, 80 to 100 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	154	215
Home Equity [Member] | LTV 100 to 120 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	68	110
Home Equity [Member] | LTV Greater than 120 Percent [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable	$ 36	57
Consumer and other [Member]
Credit Quality Indicators [Line Items]
Total mortgage loans receivable		$ 118
One- To Four-Family and Home Equity Benchmark [Member] | Financing Receivables, State, Risk [Member] | CALIFORNIA
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	32.00%	33.00%
One- To Four-Family and Home Equity Benchmark [Member] | Financing Receivables, State, Risk [Member] | NEW YORK
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	10.00%	10.00%
One- To Four-Family Benchmark [Member] | Interest only, Already Amortizing | Maximum [Member]
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	100.00%
Past due mortgage loans [Member] | Financing Receivables, State, Risk [Member] | CALIFORNIA
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	23.00%
Past due mortgage loans [Member] | Financing Receivables, State, Risk [Member] | NEW YORK
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	20.00%
Impaired mortgage loans [Member] | Financing Receivables, State, Risk [Member] | CALIFORNIA
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	41.00%
Impaired mortgage loans [Member] | Financing Receivables, State, Risk [Member] | NEW YORK
Credit Quality Indicators [Line Items]
Concentration Risk, Percentage	10.00%