Loans Receivable, Net (Details - Allowance Qualitative and Quantitative Components) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Quantitative component	$ 33	$ 157
Qualitative component	6	6
Specific valuation allowance	35	58
Total allowance for loan losses	$ 74	$ 221	$ 353	$ 404
Allowance as a % of loans receivable(1)	2.70%	5.80%
One- To Four-Family [Member]
Financing Receivable, Modifications [Line Items]
Quantitative component	$ 15	$ 34
Qualitative component	3	4
Specific valuation allowance	6	7
Total allowance for loan losses	$ 24	$ 45	40	27
Allowance as a % of loans receivable(1)	1.60%	2.30%
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Quantitative component	$ 14	$ 118
Qualitative component	3	2
Specific valuation allowance	29	51
Total allowance for loan losses	$ 46	$ 171	307	367
Allowance as a % of loans receivable(1)	4.20%	11.00%
Consumer and other [Member]
Financing Receivable, Modifications [Line Items]
Quantitative component	$ 4	$ 5
Qualitative component	0	0
Specific valuation allowance	0	0
Total allowance for loan losses	$ 4	$ 5	$ 6	$ 10
Allowance as a % of loans receivable(1)	2.10%	1.90%