Repurchase Agreements Counterparty Information (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014 Agreements
Counterparty Information [Line Items]
Equity at Risk	$ 97,517
Amount outstanding with counterparty	348,399
Weighted average interest rate, amount outstanding with counterparty	1.27%
Line of Credit Facility, Amount Outstanding	165,693
Line of Credit Facility, Maximum Borrowing Capacity	$ 250,000
Line of Credit Facility, Interest Rate at Period End	1.42%
Number of Counterparties with Borrowings Outstanding	21
Available Repurchase Agreement Counterparties	31