Fair Value of Assets and Liabilities (Details Textual) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2016 USD ($) Security	Jun. 30, 2015 Security	Dec. 31, 2015 Security
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of debt securities with other-than-temporary impairment | Security	1	1
Maturity period of short-term borrowings	one year or less
Period of swap rate	25 years
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value input discount rate	9.06%
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value input discount rate	14.01%
PreTSL XXIII
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value input discount rate	14.01%
Securities maturity date	2036-12
Securities Nonperforming Collateral Amount	$ 220.0
Securities Performing Collateral Amount	873.0
Estimated cash flows	40.7
Current principal value	$ 26.2
Trapeza IX
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value input discount rate	9.06%
Securities maturity date	2038-01
Securities Nonperforming Collateral Amount	$ 20.0
Securities Performing Collateral Amount	213.0
Estimated cash flows	38.6
Current principal value	$ 23.6
Trust preferred securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of debt securities with other-than-temporary impairment | Security	1		1
Period frequency of projected prepayment rate	1 year		1 year
Projected Prepayments, minimum fixed rate coupons	8.00%		8.00%
Projected Prepayments, percentage of fair value input for banks	1.00%		1.00%
Projected prepayment, percentage of fair value for collateral by REITs	0.00%		0.00%
Projected prepayment, percentage of fair value for collateral for insurance companies	2.00%		2.00%
Annually projected defaults percentage for healthy banks	2.00%		2.00%
Period frequency of projected default rate	2 years		2 years
Projected defaults rate for healthy banks	0.36%		0.36%
Projected Recoveries, percentage for insurance companies, REITs and insolvent banks	0.00%		0.00%
Projected recovery, percentage for projected bank deferrals	10.00%		10.00%
Projected Bank Deferrals lagged	2 years		2 years
Trust preferred securities | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value input discount rate	9.06%		10.26%
Trust preferred securities | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value input discount rate	14.01%		14.12%