Residential Loans at Amortized Cost, Net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Minimum Period After Which Residential Loans Are Placed On Non-accrual Status	90 days
Minimum Duration For Past Due Residential Loans To Be Considered As Non Performing	30 days
Recorded investment in loans 30 days or more past due	$ 68.3	$ 46.6
Loans subject to repurchase from Ginnie Mae	$ 184.3	$ 22.5
Concentrations Threshold For State Concentrations Of Residential Loans	5.00%