Supplemental Schedule of Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums, Life Insurance in Force	$ 1,686,000	$ 78,000	$ 77,000
Ceded Premiums, Life Insurance in Force	222,388,000	230,544,000	36,830,000
Assumed Premiums, Life Insurance in Force	2,995,079,000	2,943,517,000	2,889,804,000
Premiums, Net, Life Insurance in Force	$ 2,774,377,000	$ 2,713,051,000	$ 2,853,051,000
Life Insurance in Force Premiums, Percentage Assumed to Net	108.00%	108.50%	101.30%
Direct Premiums Earned	$ 43,106	$ 19,365	$ 5,224
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	843,673	447,889	319,419
Assumed Premiums Earned	9,371,308	9,098,378	8,568,222
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 8,570,741	$ 8,669,854	$ 8,254,027
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	109.30%	104.90%	103.80%
US Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 29,400	$ 9,600	$ 5,200
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	607,000	287,800	146,200
Assumed Premiums Earned	5,384,300	5,003,700	4,704,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 4,806,700	$ 4,725,500	$ 4,563,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	112.00%	105.90%	103.10%
US Non-Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 2,900	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	38,800	39,400	44,700
Assumed Premiums Earned	58,100	59,500	67,200
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 22,200	$ 20,100	$ 22,500
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	261.70%	296.00%	298.70%
Canada Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 0	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	42,300	49,600	54,200
Assumed Premiums Earned	881,200	1,002,900	993,200
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 838,900	$ 953,300	$ 939,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	105.00%	105.20%	105.80%
Canada Non-Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 0	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	0	0	0
Assumed Premiums Earned	38,000	21,300	23,300
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 38,000	$ 21,300	$ 23,300
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	100.00%	100.00%	100.00%
EMEA Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 10,700	$ 9,800	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	25,500	30,400	25,800
Assumed Premiums Earned	1,136,300	1,178,000	1,095,200
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 1,121,500	$ 1,157,400	$ 1,069,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	101.30%	101.80%	102.40%
EMEA Non-Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 100	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	89,100	0	0
Assumed Premiums Earned	260,800	216,600	151,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 171,800	$ 216,600	$ 151,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	151.80%	100.00%	100.00%
Asia Pacific Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 0	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	41,000	40,700	48,500
Assumed Premiums Earned	1,592,600	1,581,600	1,483,300
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 1,551,600	$ 1,540,900	$ 1,434,800
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	102.60%	102.60%	103.40%
Asia Pacific Non-Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 0	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	0	0	0
Assumed Premiums Earned	19,500	34,000	50,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 19,500	$ 34,000	$ 50,400
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	100.00%	100.00%	100.00%
Corporate And Other Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 0	$ 0	$ 0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	0	0	0
Assumed Premiums Earned	500	800	(200)
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 500	$ 800	$ (200)
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	100.00%	100.00%	100.00%