Investments (Net Unrealized Gains Losses on Investments by Asset Class) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Net unrealized gains (losses) on investments	$ 198,923		$ 185,050		$ 377,322
Fixed Maturities [Member]
Net unrealized gains (losses) on investments	191,339		184,891		375,409
Equity Securities [Member]
Net unrealized gains (losses) on investments	3		2		4
Other Long-term Investments [Member]
Net unrealized gains (losses) on investments	390		374		46
Affiliated Notes [Member]
Net unrealized gains (losses) on investments	2,351		3,113		4,386
Securities Related to Other Than Temporary Impairments [Member] | Fixed Maturities [Member]
Net unrealized gains (losses) on investments	1		323		545
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Net unrealized gains (losses) on investments	$ 4,839	[1]	$ (3,653)	[1]	$ (3,068)	[1]

[1] _____________ See Note 11 for more information on cash flow hedges.