SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal and state
Valuation and Qualifying Accounts Disclosure [Line Items]
Tax Act, reduction in deferred tax asset valuation allowance	$ 26.6
Federal and state | Deferred Tax Asset Valuation Allowance
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation allowance recorded on portion of deferred tax assets	387.7	$ 61.5	$ 305.3
Tax Act, reduction in deferred tax asset valuation allowance	336.3
Foreign | Deferred Tax Asset Valuation Allowance
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation allowances released	$ 43.3	$ 43.3