Funds Held - Directly Managed Realized and Unrealized Gains and Investment Income - (Details) (Funds held directly managed [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Net Realized and Unrealized Investment Gains (Losses)
Net realized and unrealized investment gains (losses) on funds held – directly managed	$ 3,433	$ (21,792)	$ 16,367
Fixed maturities and short term investments [Member]
Schedule of Net Realized and Unrealized Investment Gains (Losses)
Net realized investment gains (losses) on funds-held directly managed	1,959	6,021	8,405
Change in net unrealized investment gains (losses) on funds-held directly managed	1,938	(24,176)	6,583
Other invested assets funds held directly managed [Member]
Schedule of Net Realized and Unrealized Investment Gains (Losses)
Net realized investment gains (losses) on funds-held directly managed	53	19	0
Change in net unrealized investment gains (losses) on funds-held directly managed	$ (517)	$ (3,656)	$ 1,379