Fair Value, Company's Level 3 Assets (Servicing Related Assets) Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2021	Dec. 31, 2020
Servicing Related Assets [Abstract]
Beginning balance	[1]	$ 174,414
Changes in Fair Value due to [Abstract]
Ending balance	[1]	211,995	$ 174,414
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Servicing Related Assets [Abstract]
Beginning balance		174,414
Changes in Fair Value due to [Abstract]
Ending balance		211,995	174,414
MSRs [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Servicing Related Assets [Abstract]
Beginning balance		174,414	291,111
Purchases, sales and principal paydowns [Abstract]
Purchases		36,059	54,439
Sales			(27,754)
Other changes	[2]	(441)	(1,482)
Purchases, sales and principal paydowns		35,618	25,203
Changes in Fair Value due to [Abstract]
Changes in valuation inputs or assumptions used in valuation model		47,201	(8,318)
Other changes in fair value	[3]	(45,238)	(133,582)
Unrealized gain (loss) included in Net Income		1,963	(141,900)
Ending balance		$ 211,995	$ 174,414

[1] See Note 9 regarding the estimation of fair value, which approximates carrying value for all pools.

[2] Represents purchase price adjustments, principally contractual prepayment protection, and changes due to the Company’s repurchase of the underlying collateral.

[3] Represents changes due to realization of expected cash flows and estimated MSR runoff.