Related Party Transactions - Schedule of Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
ARMOUR management fees	$ 8,282	$ 7,709	$ 16,407	$ 15,138
Less management fees waived	(1,950)	(2,100)	(3,900)	(4,500)
Total management fee expense	6,332	5,609	12,507	10,638
U.S. Treasury Securities
Related Party Transaction [Line Items]
U.S. Treasury Securities Purchased			3,441,267	390,126
BUCKLER Securities, LLC | Corporate Joint Venture
Related Party Transaction [Line Items]
Repurchase agreements	3,434,999		3,434,999		$ 1,963,679
Collateral posted on repurchase agreements	3,605,680		3,605,680		2,036,385
Interest on repurchase agreements	$ 6,462	$ 776	7,495	$ 2,164
BUCKLER Securities, LLC | Corporate Joint Venture | U.S. Treasury Securities
Related Party Transaction [Line Items]
U.S. Treasury Securities Purchased			$ 0		$ 100,000