Investments In Securities - Weighted Average Lives of Trading Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value
1 year	$ 0	$ 0
≥ 1 year and 3 years	567,943	389,883
≥ 3 years and 5 years	1,306,206	407,656
≥ 5 years	1,036,098	86,062
Securities, trading	2,910,247	883,601
Amortized Cost
1 year	0	0
≥ 1 year and 3 years	571,872	369,600
≥ 3 years and 5 years	1,298,630	375,030
Greater than or equal to five years	1,035,018	80,214
Amortized Cost	$ 2,905,520	$ 824,844