Investments (Amortized Cost And Fair Value Of Fixed Maturity Securities In An Unrealized Loss Position By Contractual Maturity) (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Due in one year or less, cost or amortized cost	$ 52,077
Due after one year through five years, cost or amortized cost	469,320
Due after five years through ten years, cost or amortized cost	754,402
Due after ten years, cost or amortized cost	660,716
Total single maturity date, cost or amortized cost	1,936,515
Total, cost or amortized cost	2,213,031
Due in one year or less, fair value	51,667
Due after one year through five years, fair value	459,930
Due after five years through ten years, fair value	720,632
Due after ten years, fair value	607,020
Total single maturity date, fair value	1,839,249
Total, fair value	2,112,152
Residential mortgage-backed
Schedule of Available-for-sale Securities [Line Items]
Cost or amortized cost	275,176
Fair value	271,767
Asset-backed
Schedule of Available-for-sale Securities [Line Items]
Cost or amortized cost	1,340
Fair value	$ 1,136