Deferred Acquisition Costs and Value of Business Acquired (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
DAC
Balance at the beginning of the period	$ 177,781	$ 158,526	$ 253,038
Capitalized additions	94,826	57,108	47,513
Amortization and writedowns	(51,434)	(25,184)	(27,506)
Unrealized investment (gains) losses	(48,757)	(12,669)	(114,519)
Balance at the end of the period	172,416	177,781	158,526
VOBA
Balance at the beginning of the period	42,052	46,405	48,669
Amortization and writedowns	(9,045)	(3,636)	(1,837)
Unrealized investment (gains) losses	(962)	(717)	(427)
Balance at the end of the period	32,045	42,052	46,405
Total
Balance at the beginning of the period	219,833	204,931	301,707
Capitalized additions	94,826	57,108	47,513
Amortization and writedowns	(60,479)	(28,820)	(29,343)
Unrealized investment (gains) losses	(49,719)	(13,386)	(114,946)
Balance at the end of the period	204,461	219,833	204,931
Estimated future amortization of VOBA
Estimated future amortization of VOBA in 2013	4,000
Estimated future amortization of VOBA in 2014	4,000
Estimated future amortization of VOBA in 2015	4,000
Estimated future amortization of VOBA in 2016	4,000
Estimated future amortization of VOBA in 2017	$ 4,000