Segment Information - Narrative (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 segments	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of Operating Segments	3
Net results from structured products	$ 23,791	$ 5,257	$ 23,029
Alternative funds
Segment Reporting Information [Line Items]
Alternative investments, timelag for reporting	1 month
Operating affiliates
Segment Reporting Information [Line Items]
Alternative investments, timelag for reporting	3 months
Total P And C Segment [Member]
Segment Reporting Information [Line Items]
Net results from structured products	23,791	5,257	23,029
Total P And C Segment [Member] | Net Investment Income [Member]
Segment Reporting Information [Line Items]
Net results from structured products	71,900	71,700	74,600
Total P And C Segment [Member] | Interest Expense [Member]
Segment Reporting Information [Line Items]
Net results from structured products	$ (48,000)	$ (66,300)	$ (51,500)