INCOME TAXES - NARRATIVE (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Deferred tax assets more likely than not to be realized through future taxable earnings	$ 335.6	$ 604.7
Net deferred tax assets	529.3	798.4
Valuation allowance	$ 193.7	193.7
Deferred tax valuation analysis, growth rate for the next five years	3.50%
Valuation allowance model, forecast period of Model	5 years
Estimated normalized annual taxable income for the current year	$ 465.0
Adjusted average non-life taxable income	85.0
Adjusted average life taxable income	$ 380.0
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	2.19%
Net operating loss carryforwards	$ 3,010.4
Net state operating loss carryforwards	12.6	$ 14.5
Federal
Operating Loss Carryforwards [Line Items]
Valuation allowance	189.9
Net operating loss carryforwards	3,000.0
State
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 3.8