Investments in Securities - Maturity Information (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Total Carrying Amount
Total carrying amount	$ 657
One Year or Less	1
After One Year Through Five Years	19
After Five Years Through Ten Years	35
After Ten Years	602
Total Fair Value
Total Fair Value	646	$ 696
One Year or Less	1
After One Year Through Five Years	19
After Five Years Through Ten Years	34
After Ten Years	592
Agency securities
Total Carrying Amount
Total carrying amount	424
One Year or Less	0
After One Year Through Five Years	3
After Five Years Through Ten Years	19
After Ten Years	402
Total Fair Value
Total Fair Value	405	426
One Year or Less	0
After One Year Through Five Years	3
After Five Years Through Ten Years	18
After Ten Years	384
Other mortgage-related securities
Total Carrying Amount
Total carrying amount	233
One Year or Less	1
After One Year Through Five Years	16
After Five Years Through Ten Years	16
After Ten Years	200
Total Fair Value
Total Fair Value	241	$ 270
One Year or Less	1
After One Year Through Five Years	16
After Five Years Through Ten Years	16
After Ten Years	$ 208