Income Taxes - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands			12 Months Ended
	Feb. 27, 2020	Jul. 29, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Net operating loss carryforwards available for use indefinitely			$ 91,961
Aggregate tax basis of stockholders' equity in excess of assets and liabilities			$ 233,011
Aggregate tax basis of stockholders' equity in excess of assets and liabilities (in dollars per share)			$ 2.47
Common stock, shares issued (in shares)			94,152	65,290
Payment of dividends			$ 108,103	$ 86,648	$ 140,486
Estimated REIT taxable Income			$ (148,471)	$ (92,142)	$ 69,441
Percent of dividends that represent nontaxable return of capital			100.00%	100.00%	56.80%
Series B Preferred Stock
Related Party Transaction [Line Items]
Cumulative Preferred Stock dividend- Called for redemption	$ 1,375		$ 0	$ (1,375)	$ 0
Series A Preferred Stock
Related Party Transaction [Line Items]
Cumulative Preferred Stock dividend- Called for redemption		$ 375	0	0	$ (375)
Interest rate swap contracts
Related Party Transaction [Line Items]
Unrealized gain (loss) yet to be amortized			607,000	717,000
ARMOUR TRS, Inc.
Related Party Transaction [Line Items]
Income tax expense			$ 0	$ 36