Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands |
Jun. 30, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Repurchase agreements | $ 17,205,823 | $ 19,451,207 |
| Long-term Federal Home Loan Bank Advances | 50,000 | |
| Revolving credit facilities | 170,000 | 20,000 |
| Maturity Over One Year [Member] | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Revolving credit facilities | 150,000 | 0 |
| Maturity Over One Year [Member] | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Repurchase agreements | $ 300,000 | $ 112,500 |
| X | ||||||||||
- Definition The carrying value as of the balance sheet date of obligations drawn from revolving lines of credit. No definition available.
|
| X | ||||||||||
- Definition Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|