Derivative Instruments (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative, Notional Amount		$ 2,915,940	$ 2,916,181
Derivative Asset	[1]	13,130	41,842
Monetized Interest Rate Floor [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 1,500,000
Derivative Asset				$ 163,200
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred		$ 93,400
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer		4 years 8 months 12 days
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		$ 24,400
Interest rate swaps
Derivative [Line Items]
Derivative, Notional Amount		2,177,130	2,229,419
Derivative Asset		11,236	40,752
Variation Margin Impact to Positive Fair Values of Cleared Swaps		(11,300)	(587)
Variation Margin Impact to Negative Fair Values of Cleared Swaps		$ (5,500)	$ (29,700)

[1] * The fair value of each class of derivative is shown in Note 11.