INVESTMENTS - Composition of Investments in Unrealized Loss Position (Detail)	Sep. 30, 2015	Dec. 31, 2014
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	100.00%	100.00%
Percentage of Total Unrealized Losses	100.00%	100.00%
Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	96.00%	95.00%
Percentage of Total Unrealized Losses	92.00%	89.00%
Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	4.00%	5.00%
Percentage of Total Unrealized Losses	8.00%	11.00%
Public utilities | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	16.00%	13.00%
Percentage of Total Unrealized Losses	15.00%	7.00%
Sovereign and supranational | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	3.00%	3.00%
Percentage of Total Unrealized Losses	3.00%	2.00%
Banks/financial institutions | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	14.00%	14.00%
Percentage of Total Unrealized Losses	15.00%	33.00%
Other corporate | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of Total Investments in an Unrealized Loss Position	63.00%	65.00%
Percentage of Total Unrealized Losses	59.00%	47.00%
Investment Grade | Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	100.00%	100.00%
Investment Grade | Public utilities | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	95.00%	100.00%
Investment Grade | Sovereign and supranational | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	100.00%	100.00%
Investment Grade | Banks/financial institutions | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	60.00%	31.00%
Investment Grade | Other corporate | Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	86.00%	88.00%