Repurchase Agreements Counterparty Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) Agreements
Repurchase Agreement Counterparty [Line Items]
Borrowings outstanding with counterparty	$ 357,111
Weighted Average Rate	3.56%
Equity at Risk	$ 43,381
Line of Credit Facility, Amount Outstanding	212,631
Line of Credit Facility, Maximum Borrowing Capacity	$ 400,000
Line of Credit Facility, Expiration Date	May 12, 2019
Line of Credit Facility, Interest Rate at Period End	3.32%
Number of Counterparties with Borrowings Outstanding | Agreements	19
Available Repurchase Agreement Counterparties | Agreements	36