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)

v3.10.0.1
Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements $ 26,215,025 $ 21,501,250
Available-for-sale Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 23,636,891 19,780,175
Servicing Contracts [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 733,206 424,740
Cash and Cash Equivalents [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 0 15,000
Restricted Cash and Cash Equivalents [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 558,088 417,018
Due From Correspondent Brokers [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements 1,219,860 773,422
Derivative Financial Instruments, Assets [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Assets pledged or restricted as collateral for repurchase agreements $ 66,980 $ 90,895