Trading Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Trading Securities [Line Items]
Trading securities	$ 5,554,040	$ 4,707,975
Trading Securities, Net Unrealized Gain (Loss)	(25,208)	(3,560)
U.S. government securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	8,863	9,183
Trading Securities, Net Unrealized Gain (Loss)	(6)	0
Residential agency mortgage-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	5,469,676	4,669,148
Trading Securities, Net Unrealized Gain (Loss)	(24,868)	(3,624)
Municipal securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	35,894	19,172
Trading Securities, Net Unrealized Gain (Loss)	(261)	42
Other debt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	39,607	10,472
Trading Securities, Net Unrealized Gain (Loss)	$ (73)	$ 22