Borrowings (Schedule of Debt Repayments) (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Debt Instrument [Line Items]
Expected principal repayments related to consolidated residential mortgage loan securitizations	$ 1,013,000
Repurchase Agreements
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	2,364,343
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	193,521
2020 Scheduled Repayment of Principal	0
2021 Scheduled Repayment of Principal	0
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	0
Total Scheduled Repayment of Principal	2,557,864
Other Secured Borrowings
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	352,444
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	293,817
2020 Scheduled Repayment of Principal	277,390
2021 Scheduled Repayment of Principal	190,568
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	141,520
Total Scheduled Repayment of Principal	1,255,739
Senior Notes
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	0
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	0
2020 Scheduled Repayment of Principal	0
2021 Scheduled Repayment of Principal	210,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	0
Total Scheduled Repayment of Principal	210,000
Total
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	4,035,260
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	1,394,241
2020 Scheduled Repayment of Principal	1,053,445
2021 Scheduled Repayment of Principal	1,202,496
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	867,332
Total Scheduled Repayment of Principal	8,552,774
HMBS-related obligations
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	1,318,473
Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two	906,903
2020 Scheduled Repayment of Principal	776,055
2021 Scheduled Repayment of Principal	801,928
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	725,812
Total Scheduled Repayment of Principal	$ 4,529,171