Available For Sale Securities (Amortized Cost And Estimated Fair Value Of Investments Classified As Available For Sale By Contractual Maturity) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Due within one year, Amortized Cost	$ 68,250
Due after one year through five years, Amortized Cost	512
Due after five year through ten years, Amortized Cost	0
Due after ten years, Amortized Cost	0
Fixed maturities investments excluding mortgage-backed and asset-backed securities, Amortized Cost	68,762
Mortgage-backed and asset-backed securities, Amortized Cost	65,058
Amortized Cost	186,837	$ 1,562,456
Due within one year, Estimated Fair Value	68,178
Due after one year through five years, Estimated Fair Value	511
Due after five year through ten years, Estimated Fair Value	0
Due after ten years, Estimated Fair Value	0
Fixed maturities investments excluding mortgage-backed and asset-backed securities, Estimated Fair Value	68,689
Mortgage-backed and asset-backed securities, Estimated Fair Value	65,087
Estimated Fair Value	207,355	1,608,769
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	133,820	1,510,248
Estimated Fair Value	$ 133,776	$ 1,519,416