Investments (Aggregate Carrying And Approximate Market Values Of Held-To-Maturity Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, Amortized Cost	$ 83,208	$ 88,937
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	3,736	1,949
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	76
Securities held-to-maturity, Estimated Fair Value	86,944	90,810
Other Investments and Securities, at Cost	10,203	12,915
Other Investment Not Readily Marketable, Fair Value	10,203	12,915
U.S. Government Agencies Mortgage-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, Amortized Cost	79,208	84,937
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	3,736	1,949
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	76
Securities held-to-maturity, Estimated Fair Value	82,944	86,810
Asset-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, Amortized Cost	4,000	4,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Securities held-to-maturity, Estimated Fair Value	4,000	4,000
Non-Marketable Equity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Other Investments and Securities, at Cost	10,203	12,915
Other Investment Not Readily Marketable, Fair Value	$ 10,203	$ 12,915