INCOME TAXES - NARRATIVE (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jan. 01, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Deferred tax assets more likely than not to be realized through future taxable earnings	$ 599.3		$ 785.6
Net deferred tax assets	855.2		1,025.8
Valuation allowance	$ (255.9)	$ (255.9)	(240.2)
Deferred tax valuation analysis, growth rate for the next five years	3.00%
Valuation allowance model, forecast period of Model	5 years
Estimated normalized annual taxable income for the current year	$ 335.0
Adjusted average non-life taxable income	85.0
Adjusted average life taxable income	$ 250.0
Loss limitation based on income of life insurance company, percent	35.00%
Loss limitation based on loss of non-life entities, percent	35.00%
Federal long-term tax exempt rate	2.09%
Ownership change threshold restricting NOL usage	50.00%
Net operating loss carryforwards	$ 2,474.4
Net state operating loss carryforwards	$ 11.6		12.3
Future cash tax payments based on income of life insurance company, percent	65.00%
Gross deferred tax assets	$ 1,626.3	1,045.9	$ 1,647.7
Federal
Operating Loss Carryforwards [Line Items]
Valuation allowance	(245.9)
Net operating loss carryforwards	2,500.0
State
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ (10.0)
Recognition of excess tax benefits
Operating Loss Carryforwards [Line Items]
Valuation allowance		(15.7)
Gross deferred tax assets		$ 15.7