Financial Derivatives (Schedule of Derivative Activity) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Interest rate swaps
Derivative [Line Items]
Average Monthly Notional	$ 2,238,883	$ 1,343,094
TBA securities
Derivative [Line Items]
Average Monthly Notional	915,962	1,105,311
Credit default swaps
Derivative [Line Items]
Average Monthly Notional	48,880	110,084
Total return swaps
Derivative [Line Items]
Average Monthly Notional	0	2,593
Futures
Derivative [Line Items]
Average Monthly Notional	237,025	193,600
Options
Derivative [Line Items]
Average Monthly Notional	30,000	13,846
Forwards
Derivative [Line Items]
Average Monthly Notional	17,081	21,188
Warrants
Derivative [Line Items]
Average Monthly Notional	$ 3,080	$ 1,948