Restatement of Previously Issued Condensed Consolidated Financial Statements (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Fee income	$ 154,307	$ 135,160	$ 301,253	$ 262,103
Net investment income	248,603	296,086	533,965	593,267
Other realized investment (losses), net	(24,673)	36,853	(9,080)	53,794
Total realized investment gains (losses), net	(24,314)	36,853	(9,575)	53,540
Total revenues	444,953	543,490	1,077,676	1,112,388
General insurance expenses	163,704	151,858	322,182	291,615
Amortization of deferred acquisition costs and value of business acquired	14,797	16,601	30,304	32,491
Total benefits and expenses, net	453,076	442,431	981,024	937,564
Income (loss) before income taxes	(8,123)	101,059	96,652	174,824
Income tax expense (benefit)	(4,069)	35,034	33,872	58,876
Net income (loss)	(4,054)	66,025	62,780	115,948
As previously reported
Fee income	163,331		319,223
Net investment income	299,179	299,792	589,581	602,921
Other realized investment (losses), net	(1,353)	24,919	20,998	37,053
Total realized investment gains (losses), net	(994)	24,919	20,503	36,799
Total revenues	527,873	535,262	1,181,340	1,105,301
General insurance expenses	172,728		340,152
Amortization of deferred acquisition costs and value of business acquired	16,783	15,789	32,881	31,231
Total benefits and expenses, net	464,086	441,619	1,001,571	936,304
Income (loss) before income taxes	63,787	93,643	179,769	168,997
Income tax expense (benefit)	20,374	32,595	62,129	56,955
Net income (loss)	43,413	61,048	117,640	112,042
Adjustments for accounting for forward settling to be announced (TBA) security transactions, plan sponsor expense accounts, and deferred acquisition costs (DAC) | Adjustments
Fee income	(9,024)		(17,970)
Net investment income	(50,576)	(3,706)	(55,616)	(9,654)
Other realized investment (losses), net	(23,320)	11,934	(30,078)	16,741
Total realized investment gains (losses), net	(23,320)	11,934	(30,078)	16,741
Total revenues	(82,920)	8,228	(103,664)	7,087
General insurance expenses	(9,024)		(17,970)
Amortization of deferred acquisition costs and value of business acquired	(1,986)	812	(2,577)	1,260
Total benefits and expenses, net	(11,010)	812	(20,547)	1,260
Income (loss) before income taxes	(71,910)	7,416	(83,117)	5,827
Income tax expense (benefit)	(24,443)	2,439	(28,257)	1,921
Net income (loss)	$ (47,467)	$ 4,977	$ (54,860)	$ 3,906