Commitments and Contingencies (Details)	9 Months Ended
	Sep. 30, 2015 USD ($) lease
Lease Commitments
Number of operating leases | lease	2
Non-Agency MBS
MBS Purchase Commitments
Obligation to purchase MBS	$ 4,800,000
Corporate headquarters
Lease Commitments
Irrevocable standby letter of credit provided to landlord	785,000
Corporate headquarters | Low end of range
Lease Commitments
Aggregate annual lease payments	2,400,000
Corporate headquarters | High end of range
Lease Commitments
Aggregate annual lease payments	2,500,000
Off-site back-up facility | Low end of range
Lease Commitments
Aggregate annual lease payments	29,000
Off-site back-up facility | High end of range
Lease Commitments
Aggregate annual lease payments	$ 30,000