Trading Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	$ 2,250,264	$ 163,038
Corporate bonds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	5,896	6,102
US Treasury Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	2,240,236	0
Other Than Mortgage-backed Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	2,246,132	6,102
U.S. government-guaranteed - single-family MBS [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	4,047	5,344
MBS [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	4,132	156,936
GSEs - single-family [Member] | Government Sponsored Enterprises [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	85	148
GSEs - multifamily [Member] | Government Sponsored Enterprises [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	$ 0	$ 151,444