OPERATING SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Summarized financial information for the company's segments
Revenues	$ 1,063,463	$ 1,174,842	$ 2,110,819	$ 2,334,744
Pre-tax Adjusted Operating Income (Loss)	120,624	106,934	229,917	217,951
Realized (losses) gains on investments and derivatives	12,662	153,646	(9,987)	277,608
Income before income tax	133,286	260,580	219,930	495,559
Income tax expense	(43,654)	(87,787)	(71,959)	(164,149)
Net income	89,632	172,793	147,971	331,410
Adjusted operating income tax (expense) benefit	(39,222)	(34,011)	(75,454)	(66,986)
After-tax adjusted operating income	81,402	72,923	154,463	150,965
Income tax benefit (expense) on adjustments	(4,432)	(53,776)	3,495	(97,163)
Realized gain (losses) on investments
Derivative financial instruments	(63,794)	43,548	(124,694)	75,456
All other investments	53,535	88,783	76,376	170,492
Net impairment losses recognized in earnings	(2,785)	(967)	(7,986)	(3,584)
Less: related amortization	(15,703)	(13,073)	(26,447)	(17,123)
Less: VA GLWB economic cost	(10,003)	(9,209)	(19,870)	(18,121)
Operating Segment Assets
Investments and other assets	72,903,641		72,903,641		$ 70,959,790
DAC and VOBA	2,099,786		2,099,786		2,024,524
Other intangibles	665,211		665,211		687,348
Goodwill	793,470		793,470		793,470
Total assets	76,462,108		76,462,108		74,465,132
Life Marketing
Summarized financial information for the company's segments
Revenues	379,880	384,823	776,952	765,897
Pre-tax Adjusted Operating Income (Loss)	24,342	25,098	44,419	38,224
Operating Segment Assets
Investments and other assets	14,508,254		14,508,254		14,050,905
DAC and VOBA	1,265,342		1,265,342		1,218,944
Other intangibles	291,184		291,184		300,664
Goodwill	200,274		200,274		200,274
Total assets	16,265,054		16,265,054		15,770,787
Acquisitions
Summarized financial information for the company's segments
Revenues	387,464	453,848	788,831	878,655
Pre-tax Adjusted Operating Income (Loss)	68,278	45,285	121,945	113,938
Operating Segment Assets
Investments and other assets	19,543,986		19,543,986		19,679,690
DAC and VOBA	91,168		91,168		106,532
Other intangibles	35,825		35,825		37,103
Goodwill	14,524		14,524		14,524
Total assets	19,685,503		19,685,503		19,837,849
Annuities
Summarized financial information for the company's segments
Revenues	136,863	188,597	246,719	407,113
Pre-tax Adjusted Operating Income (Loss)	36,288	47,480	78,349	92,756
Operating Segment Assets
Investments and other assets	20,605,767		20,605,767		20,076,818
DAC and VOBA	704,256		704,256		655,618
Other intangibles	176,782		176,782		183,449
Goodwill	336,677		336,677		336,677
Total assets	21,823,482		21,823,482		21,252,562
Stable Value Products
Summarized financial information for the company's segments
Revenues	42,087	26,237	82,930	56,139
Pre-tax Adjusted Operating Income (Loss)	22,367	15,178	46,266	29,626
Operating Segment Assets
Investments and other assets	3,896,076		3,896,076		3,373,646
DAC and VOBA	5,512		5,512		5,455
Other intangibles	8,389		8,389		8,722
Goodwill	113,813		113,813		113,813
Total assets	4,023,790		4,023,790		3,501,636
Asset Protection
Summarized financial information for the company's segments
Revenues	93,290	76,419	183,634	150,098
Pre-tax Adjusted Operating Income (Loss)	4,674	4,141	8,624	8,397
Operating Segment Assets
Investments and other assets	887,196		887,196		858,648
DAC and VOBA	33,508		33,508		37,975
Other intangibles	138,557		138,557		143,865
Goodwill	128,182		128,182		128,182
Total assets	1,187,443		1,187,443		1,168,670
Corporate and Other
Summarized financial information for the company's segments
Revenues	23,879	44,918	31,753	76,842
Pre-tax Adjusted Operating Income (Loss)	(35,325)	$ (30,248)	(69,686)	$ (64,990)
Operating Segment Assets
Investments and other assets	13,462,362		13,462,362		12,920,083
DAC and VOBA	0		0		0
Other intangibles	14,474		14,474		13,545
Goodwill	0		0		0
Total assets	$ 13,476,836		$ 13,476,836		$ 12,933,628