Derivative Instruments - Narrative (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Dec. 31, 2013
Derivative [Line Items]
Net realized and unrealized gains (losses) on derivative instruments	$ 11,599		$ (5,105)		$ 13,409		$ 2,780
Gross amounts not offset in the balance sheet - cash collateral	3,160				3,160				0
Collateral posted to counterparty	0				0				19,847
Net results from structured products	34,885		6,053		42,838		11,229
Fair value hedges | Deposit liabilities
Derivative [Line Items]
Remaining balance	142,580		203,938		142,580		203,938
Total P&C
Derivative [Line Items]
Net results from structured products	34,885	[1]	6,053	[2]	42,838	[3]	11,229	[4]
Total P&C | Interest expense
Derivative [Line Items]
Net results from structured products	18,200		(12,100)		7,400		(24,600)
Structured Indemnity [Member] | Fair value hedges | Deposit liabilities
Derivative [Line Items]
Remaining balance	47,000				47,000
Structured Indemnity [Member] | Total P&C | Interest expense
Derivative [Line Items]
Net results from structured products	28,700
Life Funds Withheld Assets
Derivative [Line Items]
Net realized and unrealized gains (losses) on derivative instruments	$ (17,546)		$ 0		$ (17,546)		$ 0

[1] The net results from structured products include net investment income and interest expense (credit) of $16.9 million and $(18.2) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.

[2] The net results from structured products include net investment income and interest expense of $18.1 million and $12.1 million, respectively.

[3] The net results from structured products include net investment income and net interest expense (credit) of $35.7 million and $(7.4) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.

[4] The net results from structured products include net investment income and interest expense of $35.9 million and $24.6 million, respectively.