Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			4
Summary of Operations
Net interest income	$ 73	$ 63	$ 138	$ 121
Net gain (loss) on loan sales	83	55	174	100
Representation and warranty reserve - change in estimate	5	(5)	7	(4)
Other noninterest income (loss)	38	53	64	81
Benefit for loan losses	13	(6)	17	(119)
Asset resolution	(5)	(18)	(13)	(29)
Depreciation and amortization expense	(7)	(6)	(11)	(12)
Other noninterest expense	(126)	(98)	(252)	(218)
Total noninterest expense	(138)	(122)	(276)	(259)
Income (loss) before income taxes	74	38	124	(80)
Provision (benefit) for federal income taxes	28	12	46	(28)
Net income (loss)	46	26	78	(52)
Average balances
Loans held-for-sale	2,218	1,517	2,031	1,408
Loans with government guarantees	630	1,238	747	1,254
Loans held-for-investment	4,938	3,903	4,617	3,884
Total assets	11,811	9,784	11,336	9,547
Interest-bearing deposits	6,130	5,446	6,058	5,339
Mortgage Origination
Summary of Operations
Net interest income	19	14	35	26
Net gain (loss) on loan sales	88	56	183	103
Representation and warranty reserve - change in estimate	0	0	1	0
Other noninterest income (loss)	18	14	35	26
Benefit for loan losses	0	0	0	0
Asset resolution	0	0	0	0
Depreciation and amortization expense	(1)	0	(1)	(1)
Other noninterest expense	(54)	(47)	(110)	(99)
Total noninterest expense	(55)	(47)	(111)	(100)
Income (loss) before income taxes	70	37	143	55
Provision (benefit) for federal income taxes	0	0	0	0
Net income (loss)	70	37	143	55
Average balances
Loans held-for-sale	2,173	1,407	1,988	1,314
Loans with government guarantees	0	0	0	0
Loans held-for-investment	2	0	2	0
Total assets	2,268	1,567	2,122	1,466
Interest-bearing deposits	0	0	0	0
Mortgage Servicing
Summary of Operations
Net interest income	3	6	7	11
Net gain (loss) on loan sales	0	0	0	0
Representation and warranty reserve - change in estimate	5	(5)	6	(4)
Other noninterest income (loss)	14	21	27	35
Benefit for loan losses	0	0	0	0
Asset resolution	(5)	(18)	(12)	(28)
Depreciation and amortization expense	(1)	(2)	(2)	(3)
Other noninterest expense	(32)	(12)	(59)	(35)
Total noninterest expense	(38)	(32)	(73)	(66)
Income (loss) before income taxes	(16)	(10)	(33)	(24)
Provision (benefit) for federal income taxes	0	0	0	0
Net income (loss)	(16)	(10)	(33)	(24)
Average balances
Loans held-for-sale	0	0	0	0
Loans with government guarantees	630	1,238	747	1,254
Loans held-for-investment	0	0	0	0
Total assets	986	1,364	1,077	1,389
Interest-bearing deposits	0	0	0	0
Community Banking
Summary of Operations
Net interest income	43	38	81	73
Net gain (loss) on loan sales	(5)	(1)	(9)	(3)
Representation and warranty reserve - change in estimate	0	0	0	0
Other noninterest income (loss)	1	12	8	(2)
Benefit for loan losses	13	(6)	17	(119)
Asset resolution	0	0	(1)	(1)
Depreciation and amortization expense	(1)	(1)	(3)	(2)
Other noninterest expense	(38)	(37)	(78)	(78)
Total noninterest expense	(39)	(38)	(82)	(81)
Income (loss) before income taxes	13	5	15	(132)
Provision (benefit) for federal income taxes	0	0	0	0
Net income (loss)	13	5	15	(132)
Average balances
Loans held-for-sale	45	110	43	94
Loans with government guarantees	0	0	0	0
Loans held-for-investment	4,831	3,903	4,500	3,884
Total assets	4,803	3,763	4,457	3,844
Interest-bearing deposits	6,130	5,446	6,058	5,339
Other
Summary of Operations
Net interest income	8	5	15	11
Net gain (loss) on loan sales	0	0	0	0
Representation and warranty reserve - change in estimate	0	0	0	0
Other noninterest income (loss)	5	6	(6)	22
Benefit for loan losses	0	0	0	0
Asset resolution	0	0	0	0
Depreciation and amortization expense	(4)	(3)	(5)	(6)
Other noninterest expense	(2)	(2)	(5)	(6)
Total noninterest expense	(6)	(5)	(10)	(12)
Income (loss) before income taxes	7	6	(1)	21
Provision (benefit) for federal income taxes	28	12	46	(28)
Net income (loss)	(21)	(6)	(47)	49
Average balances
Loans held-for-sale	0	0	0	0
Loans with government guarantees	0	0	0	0
Loans held-for-investment	105	0	115	0
Total assets	3,754	3,090	3,680	2,848
Interest-bearing deposits	0	0	0	0
Operating Segments
Summary of Operations
Total net interest income and noninterest income	199	166	383	298
Operating Segments | Mortgage Origination
Summary of Operations
Total net interest income and noninterest income	125	84	254	155
Operating Segments | Mortgage Servicing
Summary of Operations
Total net interest income and noninterest income	22	22	40	42
Operating Segments | Community Banking
Summary of Operations
Total net interest income and noninterest income	39	49	80	68
Operating Segments | Other
Summary of Operations
Total net interest income and noninterest income	13	11	9	33
Intersegment Eliminations
Summary of Operations
Total net interest income and noninterest income	0	0	0	0
Intersegment Eliminations | Mortgage Origination
Summary of Operations
Total net interest income and noninterest income	11	2	19	6
Intersegment Eliminations | Mortgage Servicing
Summary of Operations
Total net interest income and noninterest income	(1)	4	1	9
Intersegment Eliminations | Community Banking
Summary of Operations
Total net interest income and noninterest income	(5)	(1)	(10)	(3)
Intersegment Eliminations | Other
Summary of Operations
Total net interest income and noninterest income	$ (5)	$ (5)	$ (10)	$ (12)