OPERATING SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Summarized financial information for the company's segments
Revenues	$ 1,084,388	$ 1,123,646	$ 3,276,752	$ 3,366,960
Pre-tax Adjusted Operating Income (Loss)	141,934	112,898	423,457	385,559
Realized (losses) gains on investments and derivatives	(31,084)	20,181	(74,490)	88,023
Income before income tax	110,850	133,079	348,967	473,582
Income tax (expense) benefit	(28,308)	(39,785)	(106,743)	(152,820)
Net income	82,542	93,294	242,224	320,762
Adjusted operating income tax (expense) benefit	(39,187)	(32,722)	(132,815)	(121,982)
After-tax adjusted operating income	102,747	80,176	290,642	263,577
Income tax benefit (expense) on adjustments	10,879	(7,063)	26,072	(30,838)
Realized investment (losses) gains:
Derivative financial instruments	(82,341)	116	(260,407)	(156,749)
All other investments	18,150	24,152	94,708	194,663
Net impairment losses recognized in earnings	(273)	(3,308)	(10,889)	(6,892)
Less: related amortization	(12,123)	21,532	(38,570)	4,409
Less: VA GLWB economic cost	(21,257)	(20,753)	(63,528)	(61,410)
Operating Segment Assets
Investments and other assets	75,351,823		75,351,823		$ 71,501,997
Deferred policy acquisition costs and value of business acquired	2,158,816		2,158,816		2,019,829
Other intangibles	673,588		673,588		688,083
Goodwill	793,470		793,470		793,470
Total assets	78,977,697		78,977,697		75,003,379
Life Marketing
Summarized financial information for the company's segments
Revenues	424,165	409,423	1,252,603	1,231,397
Pre-tax Adjusted Operating Income (Loss)	8,969	(1,306)	51,157	36,957
Operating Segment Assets
Investments and other assets	14,700,406		14,700,406		14,050,170
Deferred policy acquisition costs and value of business acquired	1,295,708		1,295,708		1,218,944
Other intangibles	287,120		287,120		301,399
Goodwill	200,274		200,274		200,274
Total assets	16,483,508		16,483,508		15,770,787
Acquisitions
Summarized financial information for the company's segments
Revenues	375,819	391,017	1,164,650	1,269,672
Pre-tax Adjusted Operating Income (Loss)	62,880	70,157	184,825	184,095
Operating Segment Assets
Investments and other assets	19,681,306		19,681,306		19,679,690
Deferred policy acquisition costs and value of business acquired	77,157		77,157		106,532
Other intangibles	35,187		35,187		37,103
Goodwill	14,524		14,524		14,524
Total assets	19,808,174		19,808,174		19,837,849
Annuities
Summarized financial information for the company's segments
Revenues	97,488	174,798	318,452	410,455
Pre-tax Adjusted Operating Income (Loss)	62,000	53,666	161,585	164,196
Operating Segment Assets
Investments and other assets	20,617,917		20,617,917		20,243,333
Deferred policy acquisition costs and value of business acquired	752,540		752,540		655,618
Other intangibles	173,450		173,450		183,449
Goodwill	336,677		336,677		336,677
Total assets	21,880,584		21,880,584		21,419,077
Stable Value Products
Summarized financial information for the company's segments
Revenues	49,933	27,380	132,863	83,519
Pre-tax Adjusted Operating Income (Loss)	27,992	14,700	74,258	44,326
Operating Segment Assets
Investments and other assets	4,664,251		4,664,251		3,373,646
Deferred policy acquisition costs and value of business acquired	7,605		7,605		5,455
Other intangibles	8,222		8,222		8,722
Goodwill	113,813		113,813		113,813
Total assets	4,793,891		4,793,891		3,501,636
Asset Protection
Summarized financial information for the company's segments
Revenues	83,597	69,306	246,142	201,041
Pre-tax Adjusted Operating Income (Loss)	6,963	5,455	19,098	16,216
Operating Segment Assets
Investments and other assets	914,658		914,658		1,013,399
Deferred policy acquisition costs and value of business acquired	25,806		25,806		33,280
Other intangibles	135,895		135,895		143,865
Goodwill	128,182		128,182		128,182
Total assets	1,204,541		1,204,541		1,318,726
Corporate and Other
Summarized financial information for the company's segments
Revenues	53,386	51,722	162,042	170,876
Pre-tax Adjusted Operating Income (Loss)	(26,870)	$ (29,774)	(67,466)	$ (60,231)
Operating Segment Assets
Investments and other assets	14,773,285		14,773,285		13,141,759
Deferred policy acquisition costs and value of business acquired	0		0		0
Other intangibles	33,714		33,714		13,545
Goodwill	0		0		0
Total assets	$ 14,806,999		$ 14,806,999		$ 13,155,304