Segment Information - Narrative (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) segments	Sep. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of segments | segments				2
Net results from structured products	[1]	$ 7,708	$ 4,437	$ 11,737	$ 14,719
Net investment income | Total P&C
Segment Reporting Information [Line Items]
Net results from structured products		14,100	15,600	40,900	46,700
Interest Expense [Member] | Total P&C
Segment Reporting Information [Line Items]
Net results from structured products		$ (6,400)	$ (11,100)	$ (29,100)	$ (31,700)

[1] The net results from P&C structured products include net investment income and interest expense of $40.9 million and $29.1 million, respectively.