ACCOUNTING FOR DERIVATIVES - DERIVATIVES WITH MASTER NETTING ARRANGEMENTS (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fixed Index Call Options [Member]
Derivative [Line Items]
Gross amounts recognized	$ 84.7	$ 41.0
Gross amounts offset in the balance sheet	0.0	0.0
Net amounts of assets presented in the balance sheet	84.7	41.0
Financial instruments	0.0	0.0
Cash collateral received	0.0	0.0
Net amount	84.7	41.0
Interest Rate Futures [Member]
Derivative [Line Items]
Gross amounts recognized	0.0	0.1
Gross amounts offset in the balance sheet	0.0	1.5
Net amounts of assets presented in the balance sheet	0.0	1.6
Financial instruments	0.0	0.0
Cash collateral received	0.0	0.0
Net amount	$ 0.0	$ 1.6