Sch IV Reinsurance (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	$ 305,129	$ 296,352	$ 286,755
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	28,863	30,766	31,986
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	638	439	1,564
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	276,904	266,025	256,333
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	0.20%	0.20%	0.60%
Life Insurance in Force [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	51,955,217	49,778,838	48,386,637
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	11,999,297	11,031,493	10,213,574
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	612,850	588,791	92,321
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	40,568,770	39,336,136	38,265,384
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	1.50%	1.50%	0.20%
Insurance sensitive product charges [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	102,027	97,725	93,408
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	1,010	1,061	1,091
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	393	439	1,564
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	101,410	97,103	93,881
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	0.40%	0.50%	1.70%
Life insurance - traditional [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	194,090	189,159	183,432
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	19,249	20,640	21,376
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	245	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	175,086	168,519	162,056
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	0.10%	0.00%	0.00%
Accident and Health Insurance Segment [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	9,012	9,468	9,915
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	8,604	9,065	9,519
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	0	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 408	$ 403	$ 396
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%