Sch IV Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums, Life Insurance in Force	$ 60,753,614	$ 59,136,803	$ 57,010,809
Ceded Premiums, Life Insurance in Force	14,258,000	14,263,000	13,837,869
Assumed Premiums, Life Insurance in Force	524,000	552,000	592,022
Premiums, Net, Life Insurance in Force	$ 47,018,695	$ 45,424,946	$ 43,764,962
Life Insurance in Force Premiums, Percentage Assumed to Net	1.10%	1.20%	1.40%
Direct Premiums Earned	$ 339,601	$ 336,718	$ 325,182
Ceded Premiums Earned	33,058	33,462	32,513
Assumed Premiums Earned	2,670	2,751	783
Premiums Earned, Net	$ 309,213	$ 306,007	$ 293,452
Premiums, Percentage Assumed to Net	0.90%	0.90%	0.30%
Interest sensitive product charges
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 110,608	$ 113,221	$ 110,431
Ceded Premiums Earned	1,003	1,024	1,026
Assumed Premiums Earned	2,323	2,387	365
Premiums Earned, Net	$ 111,928	$ 114,584	$ 109,770
Premiums, Percentage Assumed to Net	2.10%	2.10%	0.30%
Traditional life insurance premiums
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 222,037	$ 215,936	$ 206,701
Ceded Premiums Earned	25,470	25,344	23,819
Assumed Premiums Earned	347	364	418
Premiums Earned, Net	$ 196,914	$ 190,956	$ 183,300
Premiums, Percentage Assumed to Net	0.20%	0.20%	0.20%
Accident and health premiums
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 6,956	$ 7,561	$ 8,050
Ceded Premiums Earned	6,585	7,094	7,668
Assumed Premiums Earned	0	0	0
Premiums Earned, Net	$ 371	$ 467	$ 382
Premiums, Percentage Assumed to Net	0.00%	0.00%	0.00%