Financing - Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged as collateral for repurchase agreements	$ 9,684,418	$ 8,701,825
Repurchase agreements	8,782,622	7,805,057
Available-For-Sale Securities
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged as collateral for repurchase agreements	8,207,842	7,097,561
Mortgage Servicing Rights
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged as collateral for repurchase agreements	1,328,463	1,355,639
Repurchase agreements	790,000	755,000
Mortgage Servicing Rights \| Variable Funding Note
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	790,000	755,000
Restricted cash
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged as collateral for repurchase agreements	44,216	218,363
Due from counterparties
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged as collateral for repurchase agreements	38,221	25,231
Derivative Assets
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged as collateral for repurchase agreements	$ 65,676	$ 5,031