Fair Value Measurements (Details 1) - Level 3 - Fair Value, Measurements, Recurring	6 Months Ended
	Jun. 30, 2019
Measurement Input, Prepayment Rate | Minimum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.036
Measurement Input, Prepayment Rate | Minimum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.036
Measurement Input, Prepayment Rate | Minimum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.120
Measurement Input, Prepayment Rate | Maximum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	1.000
Measurement Input, Prepayment Rate | Maximum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.0100
Measurement Input, Prepayment Rate | Maximum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.150
Measurement Input, Prepayment Rate | Weighted Average | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.112
Measurement Input, Prepayment Rate | Weighted Average | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.112
Measurement Input, Prepayment Rate | Weighted Average | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.137
Measurement Input, Default Rate | Minimum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.004
Measurement Input, Default Rate | Minimum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.004
Measurement Input, Default Rate | Minimum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.020
Measurement Input, Default Rate | Maximum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.820
Measurement Input, Default Rate | Maximum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.8200
Measurement Input, Default Rate | Maximum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.02
Measurement Input, Default Rate | Weighted Average | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.019
Measurement Input, Default Rate | Weighted Average | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.019
Measurement Input, Default Rate | Weighted Average | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.020
Measurement Input, Loss Severity | Minimum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.015
Measurement Input, Loss Severity | Minimum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.015
Measurement Input, Loss Severity | Minimum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.600
Measurement Input, Loss Severity | Maximum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	1.458
Measurement Input, Loss Severity | Maximum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	1.4580
Measurement Input, Loss Severity | Maximum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.60
Measurement Input, Loss Severity | Weighted Average | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.578
Measurement Input, Loss Severity | Weighted Average | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.578
Measurement Input, Loss Severity | Weighted Average | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.600
Measurement Input, Discount Rate | Minimum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.025
Measurement Input, Discount Rate | Minimum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.025
Measurement Input, Discount Rate | Minimum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.032
Measurement Input, Discount Rate | Maximum | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.093
Measurement Input, Discount Rate | Maximum | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.0930
Measurement Input, Discount Rate | Maximum | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.052
Measurement Input, Discount Rate | Weighted Average | Covered Private Label Collateralized Mortgage Obligations Member [Domain]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.064
Measurement Input, Discount Rate | Weighted Average | Private label collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Private Label Collateralized Mortgage Obligations, Measurement Input	0.064
Measurement Input, Discount Rate | Weighted Average | Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset-Backed Securities, Measurement Input	0.043