Investments (Other Invested Assets) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Other Investments [Line Items]
Other invested assets	$ 1,234,779	$ 1,324,960
Equity securities
Other Investments [Line Items]
Other invested assets	282,015	405,731
Limited Partner [Member]
Other Investments [Line Items]
Other invested assets	403,874	411,456
Structured loans
Other Investments [Line Items]
Other invested assets	209,590	223,549
Derivatives
Other Investments [Line Items]
Other invested assets	121,173	75,227
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other Investments [Line Items]
Other invested assets	147,342	138,892
Other
Other Investments [Line Items]
Other invested assets	$ 70,785	$ 70,105