Fair Value Measurements (Details 2) (Recurring basis, Level 3, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended				9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Fixed maturities available-for-sale, Corporate debt securities	Sep. 30, 2012 Fixed maturities available-for-sale, Corporate debt securities	Sep. 30, 2013 Fixed maturities available-for-sale, Corporate debt securities	Sep. 30, 2012 Fixed maturities available-for-sale, Corporate debt securities	Sep. 30, 2013 Fixed maturities available-for-sale, Asset-backed securities	Sep. 30, 2012 Fixed maturities available-for-sale, Asset-backed securities	Sep. 30, 2013 Fixed maturities available-for-sale, Asset-backed securities	Sep. 30, 2012 Fixed maturities available-for-sale, Asset-backed securities	Sep. 30, 2012 Fixed maturities available-for-sale, Collateralized debt obligations	Sep. 30, 2012 Fixed maturities available-for-sale, Collateralized debt obligations	Sep. 30, 2013 Fixed maturities available-for-sale, Collateralized debt obligations	Jun. 30, 2013 Fixed maturities available-for-sale, Collateralized debt obligations	Dec. 31, 2012 Fixed maturities available-for-sale, Collateralized debt obligations	Sep. 30, 2012 Separate accounts
Recurring Level 3 financial assets and liabilities
Balance at the beginning of the period	$ 262,596	$ 274,514	$ 267,392	$ 317,657	$ 1,796	$ 5,460	$ 1,822	$ 36,496	$ 260,768	$ 269,035	$ 265,538	$ 279,021	$ 19	$ 22	$ 32	$ 32	$ 32	$ 2,118
Realized and unrealized gains (losses) included in net income				(1,781)				(66)										(1,715)
Realized and unrealized gains (losses) included in other comprehensive income (loss)	6,662	12,592	25,233	24,006	(5)	33	(28)	70	6,667	12,547	25,261	22,298	12	11				1,627
Sales				(3,595)				(1,598)										(1,997)
Settlements	(12,085)	(9,769)	(35,452)	(25,332)	1	16	(2)	(795)	(12,086)	(9,786)	(35,450)	(24,503)	1	(1)				(33)
Transfers out of Level 3		(3,734)		(37,352)		(3,734)		(32,332)				(5,020)
Balance at the end of the period	$ 257,173	$ 273,603	$ 257,173	$ 273,603	$ 1,792	$ 1,775	$ 1,792	$ 1,775	$ 255,349	$ 271,796	$ 255,349	$ 271,796	$ 32	$ 32	$ 32	$ 32	$ 32