Short-Term Debt - Mortgage Loans Sold Under Agreement to Repurchase by Counterparty (Details) - Loan Repo Facility $ in Thousands	Jun. 30, 2025 USD ($)
Atlas Securitized Products, L.P., Goldman Sachs Bank USA, Nomura Corporate Funding Americas and Mizuho Bank, Ltd
Mortgage loans sold under agreement to repurchase
Amount at risk	$ 6,174,715
Royal Bank of Canada
Mortgage loans sold under agreement to repurchase
Amount at risk	33,779
Bank of America, N.A.
Mortgage loans sold under agreement to repurchase
Amount at risk	92,204
Atlas Securitized Products, L.P.
Mortgage loans sold under agreement to repurchase
Amount at risk	158,877
BNP Paribas
Mortgage loans sold under agreement to repurchase
Amount at risk	13,186
Barclays Capital
Mortgage loans sold under agreement to repurchase
Amount at risk	14,165
Nomura Corporate Funding Americas
Mortgage loans sold under agreement to repurchase
Amount at risk	19,151
Citibank, N.A.
Mortgage loans sold under agreement to repurchase
Amount at risk	29,756
Wells Fargo Bank, N.A.
Mortgage loans sold under agreement to repurchase
Amount at risk	15,359
Morgan Stanley Bank, N.A.
Mortgage loans sold under agreement to repurchase
Amount at risk	18,275
Goldman Sachs
Mortgage loans sold under agreement to repurchase
Amount at risk	2,222
Mizuho Bank, Ltd.
Mortgage loans sold under agreement to repurchase
Amount at risk	8,733
JPMorgan Chase Bank, N.A.
Mortgage loans sold under agreement to repurchase
Amount at risk	$ 38,981