INVESTMENTS - Composition of Investments in Unrealized Loss Position in Bank and Financial Institution Sector (Detail) (Banks/financial Institutions)	Jun. 30, 2012	Dec. 31, 2011
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	44.00%	46.00%
Percentage of Total Unrealized Losses	62.00%	62.00%
Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	34.00%	37.00%
Percentage of Total Unrealized Losses	42.00%	44.00%
Perpetual Securities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	10.00%	9.00%
Percentage of Total Unrealized Losses	20.00%	18.00%
Perpetual Securities | Upper Tier II
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	6.00%	4.00%
Percentage of Total Unrealized Losses	10.00%	6.00%
Perpetual Securities | Tier I
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	4.00%	5.00%
Percentage of Total Unrealized Losses	10.00%	12.00%