Investments (Other Invested Assets) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Other Investments [Line Items]
Other invested assets	$ 1,165,021	$ 1,324,960
Equity securities
Other Investments [Line Items]
Other invested assets	161,950	405,731
Limited Partner [Member]
Other Investments [Line Items]
Other invested assets	439,695	411,456
Structured loans
Other Investments [Line Items]
Other invested assets	182,977	223,549
Derivatives
Other Investments [Line Items]
Other invested assets	163,554	75,227
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other Investments [Line Items]
Other invested assets	142,125	138,892
Other
Other Investments [Line Items]
Other invested assets	$ 74,720	$ 70,105