Derivative Instruments (Consolidated Balance Sheets And Fair Value Of The Principal Derivative Instruments) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Other Assets
Derivative Assets
Gross Amounts of Recognized Assets	$ 7,603	$ 6,968
Gross Amounts Offset in the Balance Sheet	521	1,662
Net Amounts of Assets Presented in the Balance Sheet	7,082	5,306
Collateral	447	0
Net Amount	6,635	5,306
Other Assets | Interest Rate Contracts
Derivative Assets
Gross Amounts of Recognized Assets	1,514	1,059
Gross Amounts Offset in the Balance Sheet	262	937
Net Amounts of Assets Presented in the Balance Sheet	1,252	122
Collateral	0	0
Net Amount	1,252	122
Other Assets | Foreign Currency Forward Contracts, Underwriting and Non-investment Operations
Derivative Assets
Gross Amounts of Recognized Assets	5,236	4,645
Gross Amounts Offset in the Balance Sheet	73	82
Net Amounts of Assets Presented in the Balance Sheet	5,163	4,563
Collateral	0	0
Net Amount	5,163	4,563
Other Assets | Foreign Currency Forward Contracts, Investment Operations
Derivative Assets
Gross Amounts of Recognized Assets	127	1,007
Gross Amounts Offset in the Balance Sheet	87	599
Net Amounts of Assets Presented in the Balance Sheet	40	408
Collateral	0	0
Net Amount	40	408
Other Assets | Credit Default Swaps
Derivative Assets
Gross Amounts of Recognized Assets	726	257
Gross Amounts Offset in the Balance Sheet	99	44
Net Amounts of Assets Presented in the Balance Sheet	627	213
Collateral	447	0
Net Amount	180	213
Other Liabilities
Derivative Liabilities
Gross Amounts of Recognized Liabilities	6,827	5,481
Gross Amounts Offset in the Balance Sheet	2,113	1,661
Net Amounts of Liabilities Presented in the Balance Sheet	4,714	3,820
Collateral Pledged	396	1,803
Net Amount	4,318	2,017
Other Liabilities | Interest Rate Contracts
Derivative Liabilities
Gross Amounts of Recognized Liabilities	430	2,293
Gross Amounts Offset in the Balance Sheet	262	937
Net Amounts of Liabilities Presented in the Balance Sheet	168	1,356
Collateral Pledged	151	1,356
Net Amount	17	0
Other Liabilities | Foreign Currency Forward Contracts, Underwriting and Non-investment Operations
Derivative Liabilities
Gross Amounts of Recognized Liabilities	4,968	1,891
Gross Amounts Offset in the Balance Sheet	1,665	81
Net Amounts of Liabilities Presented in the Balance Sheet	3,303	1,810
Collateral Pledged	0	0
Net Amount	3,303	1,810
Other Liabilities | Foreign Currency Forward Contracts, Investment Operations
Derivative Liabilities
Gross Amounts of Recognized Liabilities	1,060	806
Gross Amounts Offset in the Balance Sheet	87	599
Net Amounts of Liabilities Presented in the Balance Sheet	973	207
Collateral Pledged	0	0
Net Amount	973	207
Other Liabilities | Credit Default Swaps
Derivative Liabilities
Gross Amounts of Recognized Liabilities	369	491
Gross Amounts Offset in the Balance Sheet	99	44
Net Amounts of Liabilities Presented in the Balance Sheet	270	447
Collateral Pledged	245	447
Net Amount	$ 25	$ 0