Regulatory Capital Table - ERCF Capital Requirements (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Compliance with Regulatory Capital Requirements - ERCF [Abstract]
Adjusted total assets	$ 3,864,000	$ 3,817,000
Risk-weighted assets (standardized approach)	1,114,000	1,118,000
Available Capital (Deficit) [Member]
Risk-based capital amounts [Abstract]
Total capital (statutory)	0	(6,000)
CET1 capital	(27,000)	(32,000)
Tier 1 capital	(13,000)	(18,000)
Adjusted total capital	$ (13,000)	$ (18,000)
Risk-based capital ratios [Abstract]
Total capital (statutory)	0.00%	(0.50%)
CET1 capital	(2.40%)	(2.90%)
Tier 1 capital	(1.20%)	(1.60%)
Adjusted total capital	(1.20%)	(1.60%)
Leverage capital amounts: [Abstract]
Core capital (statutory)	$ (8,000)	$ (13,000)
Tier 1 capital	$ (13,000)	$ (18,000)
Leverage capital ratios [Abstract]
Core capital (statutory)	(0.20%)	(0.30%)
Tier 1 capital	(0.30%)	(0.50%)
Minimum Capital Requirement [Member]
Risk-based capital amounts [Abstract]
Total capital (statutory)	$ 89,000	$ 89,000
CET1 capital	50,000	50,000
Tier 1 capital	67,000	67,000
Adjusted total capital	$ 89,000	$ 89,000
Risk-based capital ratios [Abstract]
Total capital (statutory)	8.00%	8.00%
CET1 capital	4.50%	4.50%
Tier 1 capital	6.00%	6.00%
Adjusted total capital	8.00%	8.00%
Leverage capital amounts: [Abstract]
Core capital (statutory)	$ 97,000	$ 95,000
Tier 1 capital	$ 97,000	$ 95,000
Leverage capital ratios [Abstract]
Core capital (statutory)	2.50%	2.50%
Tier 1 capital	2.50%	2.50%
Capital Requirement Including Buffer [Member]
Risk-based capital amounts [Abstract]
Total capital (statutory)	$ 89,000	$ 89,000
CET1 capital	109,000	107,000
Tier 1 capital	126,000	124,000
Adjusted total capital	$ 148,000	$ 146,000
Risk-based capital ratios [Abstract]
Total capital (statutory)	8.00%	8.00%
CET1 capital	9.80%	9.60%
Tier 1 capital	11.30%	11.10%
Adjusted total capital	13.30%	13.10%
Leverage capital amounts: [Abstract]
Core capital (statutory)	$ 97,000	$ 95,000
Tier 1 capital	$ 112,000	$ 109,000
Leverage capital ratios [Abstract]
Core capital (statutory)	2.50%	2.50%
Tier 1 capital	2.90%	2.90%