Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged or restricted as collateral for repurchase agreements	$ 8,553,586	$ 15,787,325
Available-for-sale securities
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged or restricted as collateral for repurchase agreements	7,009,449	14,633,217
Mortgage servicing rights
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged or restricted as collateral for repurchase agreements	725,985	0
Restricted cash
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged or restricted as collateral for repurchase agreements	747,779	1,071,239
Due from counterparties
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged or restricted as collateral for repurchase agreements	30,764	21,312
Derivative assets
Assets Sold under Agreements to Repurchase [Line Items]
Assets pledged or restricted as collateral for repurchase agreements	$ 39,609	$ 61,557