SEGMENT INFORMATION (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Number of operating segments of the Company	3
Net Investment Income	$ 1,063,199,000	$ 1,116,530,000	$ 1,215,173,000
Interest Expense	205,592,000	213,643,000	216,504,000
Structured Products P And C Segment [Member]
Net Investment Income	74,600,000	69,000,000	79,300,000
Interest Expense	51,500,000	52,900,000	36,300,000
Segment Operating Expenses		1,600,000
Corporate [Member]
Net Investment Income		12,500,000	25,300,000
Interest Expense		1,700,000	7,400,000
Segment Operating Expenses		$ 1,000,000	$ 1,300,000