Insurance In Force (Schedule Of Geographical Distribution Of Insurance In Force) (Detail) (USD $) In Billions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Insurance in Force	$ 679.1	$ 840.1
% of Insurance in Force	100.00%	100.00%
California [Member]
Insurance in Force	104.7	125.0
% of Insurance in Force	15.40%	14.90%
New York [Member]
Insurance in Force	48.7	62.3
% of Insurance in Force	7.20%	7.40%
Florida [Member]
Insurance in Force	36.8	47.9
% of Insurance in Force	5.40%	5.70%
Texas [Member]
Insurance in Force	33.9	41.7
% of Insurance in Force	5.00%	5.00%
Illinois [Member]
Insurance in Force	33.3	41.2
% of Insurance in Force	4.90%	4.90%
New Jersey [Member]
Insurance in Force	24.1	30.3
% of Insurance in Force	3.60%	3.60%
Michigan [Member]
Insurance in Force	17.6	21.1
% of Insurance in Force	2.60%	2.50%
Washington [Member]
Insurance in Force	15.9	22.8
% of Insurance in Force	2.30%	2.70%
Pennsylvania [Member]
Insurance in Force	14.5	18.5
% of Insurance in Force	2.10%	2.20%
Colorado [Member]
Insurance in Force	11.1	13.5
% of Insurance in Force	1.60%	1.60%
Sub-Total Insurance In Force [Member]
Insurance in Force	340.6	424.3
% of Insurance in Force	50.10%	50.50%
Nationally Diversified [Member]
Insurance in Force	80.0	102.4
% of Insurance in Force	11.80%	12.20%
Other States [Member]
Insurance in Force	183.7	225.8
% of Insurance in Force	27.10%	26.90%
United States [Member]
Insurance in Force	604.3	752.5
% of Insurance in Force	89.00%	89.60%
Internationally Diversified [Member]
Insurance in Force	18.9	28.9
% of Insurance in Force	2.80%	3.40%
Country Specific [Member]
Insurance in Force	55.9	58.7
% of Insurance in Force	8.20%	7.00%
Non-United States [Member]
Insurance in Force	$ 74.8	$ 87.6
% of Insurance in Force	11.00%	10.40%