Available For Sale Securities (Amortized Cost And Estimated Fair Value Of Investments Classified As Available For Sale By Contractual Maturity) (Details) $ in Thousands	Jun. 30, 2015 USD ($)
Investments [Abstract]
Due within one year, Amortized Cost	$ 421,268
Due after one year through five years, Amortized Cost	2,580
Due after five years 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	423,848
Mortgage-backed and asset-backed securities, Amortized Cost	386,944
Total fixed maturities investments, Amortized Cost	810,792
Due within one year, Estimated Fair Value	421,379
Due after one year through five years, Estimated Fair Value	2,583
Due after five years 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	423,962
Mortgage-backed and asset-backed securities, Estimated Fair Value	389,888
Total fixed maturities investments, Estimated Fair Value	$ 813,850