Investments (Other Invested Assets) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Other Investments [Line Items]
Other invested assets	$ 1,128,375	$ 1,324,960
Equity securities
Other Investments [Line Items]
Other invested assets	140,744	405,731
Limited Partner [Member]
Other Investments [Line Items]
Other invested assets	425,100	411,456
Structured loans
Other Investments [Line Items]
Other invested assets	193,462	223,549
Derivatives
Other Investments [Line Items]
Other invested assets	135,771	75,227
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other Investments [Line Items]
Other invested assets	151,726	138,892
Other
Other Investments [Line Items]
Other invested assets	$ 81,572	$ 70,105