OPERATING SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Summarized financial information for the company's segments
Revenues	$ 1,165,832	$ 1,105,297
Pre-tax Adjusted Operating Income (Loss)	92,821	135,389
Realized (losses) gains on investments and derivatives	(1,023)	(23,040)
Income before income tax	91,798	112,349
Income tax expense	(17,686)	(36,935)
Net income	74,112	75,414
Adjusted operating income tax (expense) benefit	(18,044)	(44,999)
After-tax adjusted operating income	74,777	90,390
Income tax benefit (expense) on adjustments	358	8,064
Realized investment (losses) gains:
Derivative financial instruments	78,059	(69,878)
All other investments	(87,599)	22,841
Net impairment losses recognized in earnings	(3,645)	(7,831)
Less: related amortization	9,156	(10,744)
Less: VA GLWB economic cost	(21,318)	(21,084)
Operating Segment Assets
Investments and other assets	74,132,583		$ 75,973,148
DAC and VOBA	2,434,154		2,199,577
Other intangibles	651,707		663,572
Goodwill	793,470		793,470
Total assets	78,011,914		79,629,767
Life Marketing
Summarized financial information for the company's segments
Revenues	434,916	421,392
Pre-tax Adjusted Operating Income (Loss)	(17,849)	18,945
Operating Segment Assets
Investments and other assets	14,744,343		14,914,418
DAC and VOBA	1,374,149		1,320,776
Other intangibles	277,489		282,361
Goodwill	200,274		200,274
Total assets	16,596,255		16,717,829
Acquisitions
Summarized financial information for the company's segments
Revenues	379,094	401,367
Pre-tax Adjusted Operating Income (Loss)	55,520	53,667
Operating Segment Assets
Investments and other assets	19,275,508		19,588,133
DAC and VOBA	90,466		74,862
Other intangibles	33,909		34,548
Goodwill	14,524		14,524
Total assets	19,414,407		19,712,067
Annuities
Summarized financial information for the company's segments
Revenues	150,713	108,642
Pre-tax Adjusted Operating Income (Loss)	40,531	53,007
Operating Segment Assets
Investments and other assets	20,535,539		20,938,409
DAC and VOBA	800,941		772,634
Other intangibles	166,784		170,117
Goodwill	336,677		336,677
Total assets	21,839,941		22,217,837
Stable Value Products
Summarized financial information for the company's segments
Revenues	53,868	40,843
Pre-tax Adjusted Operating Income (Loss)	29,080	23,899
Operating Segment Assets
Investments and other assets	4,571,793		4,569,639
DAC and VOBA	6,133		6,864
Other intangibles	7,889		8,056
Goodwill	113,813		113,813
Total assets	4,699,628		4,698,372
Asset Protection
Summarized financial information for the company's segments
Revenues	76,375	80,083
Pre-tax Adjusted Operating Income (Loss)	6,218	5,599
Operating Segment Assets
Investments and other assets	1,016,586		918,952
DAC and VOBA	162,465		24,441
Other intangibles	130,573		133,234
Goodwill	128,182		128,182
Total assets	1,437,806		1,204,809
Corporate and Other
Summarized financial information for the company's segments
Revenues	70,866	52,970
Pre-tax Adjusted Operating Income (Loss)	(20,679)	$ (19,728)
Operating Segment Assets
Investments and other assets	13,988,814		15,043,597
DAC and VOBA	0		0
Other intangibles	35,063		35,256
Goodwill	0		0
Total assets	$ 14,023,877		$ 15,078,853