Securities In An Unrealized Loss Position Non-Investment Grade Fixed Maturity Securities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	$ 2,559,336	$ 3,441,075
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	478,277	719,251
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	1,338,039	1,118,447
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	286,776	986,958
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	203,167	320,215
Noninvestment Grade Investments at Loss Less than 5 Million
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	18
Aggregate fair value of securities in a continuous unrealized loss position	69,724
Gross Unrealized Loss	2,258
Noninvestment Grade Investments at Loss Less than 5 Million | Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	9
Aggregate fair value of securities in a continuous unrealized loss position	42,230
Gross Unrealized Loss	1,611
Noninvestment Grade Investments at Loss Less than 5 Million | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	9
Aggregate fair value of securities in a continuous unrealized loss position	27,494
Gross Unrealized Loss	647
Noninvestment Grade Investments at Loss Less than 5 Million | Foreign government
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	0
Aggregate fair value of securities in a continuous unrealized loss position	0
Gross Unrealized Loss	$ 0