Financing Arrangements, Residential Mortgage Loans - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 14, 2015	Nov. 25, 2015	Dec. 31, 2014	Dec. 16, 2014
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreement, outstanding balance	$ 456,400,000			$ 652,000,000
Pool of Distressed Residential Mortgage Loans | Deutsche Bank AG, Cayman Islands Branch
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreement, principal		$ 250,000,000			$ 260,000,000
Repurchase agreement, outstanding balance	$ 214,500,000			$ 238,900,000
Repurchase agreement, interest rate (as a percent)	2.92%			2.66%
Pool of Distressed Residential Mortgage Loans | LIBOR | Deutsche Bank AG, Cayman Islands Branch
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Basis spread on variable rate (as a percent)	2.50%
Residential Mortgage | Deutsche Bank AG, Cayman Islands Branch
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreement, principal			$ 100,000,000
Repurchase agreement, outstanding balance	$ 0
Residential Mortgage | LIBOR | Deutsche Bank AG, Cayman Islands Branch
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Basis spread on variable rate (as a percent)	4.00%