Quarterly report pursuant to Section 13 or 15(d)

Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets (Details)

v3.19.1
Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements $ 21,859,645 $ 25,530,229
Available-for-sale Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 20,925,201 24,240,507
Mortgage Servicing Rights [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 756,573 685,683
Restricted Cash and Cash Equivalents [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 66,296 416,696
Due From Counterparties [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 35,619 110,695
Derivative Financial Instruments, Assets [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 71,696 70,191
US Treasury Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements $ 4,260 $ 6,457