Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Effective income tax rate reconciliation, at federal statutory income tax rate, percent	35.00%
Income tax (provision) benefit	$ (0.1)	$ 0.1
Net cash paid for income taxes	0.1	1.9
Valuation allowance	339.3	325.3
Deferred tax liabilities	7.3	9.4
Net deferred tax assets	6.3
Unremitted foreign earnings in deferred tax liabilities related to foreign tax withholding	1.0
Unrecognized tax benefits, excluding accrued interest and penalties	1.3	1.7	$ 2.1
Unrecognized tax benefits that would impact effective tax rate	1.3
Interest and penalties recorded (benefit) expense	0.0	0.1
Interest and penalties accrued	0.0	$ 0.1
Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	649.6
Operating loss carry forwards, after application of internal revenue code section 382	27.9
Capital Loss Carryforward | Internal Revenue Service (IRS) | Between 2018 and 2020
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	36.9
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	555.1
State and Local Jurisdiction | Expiring between 2017 and 2019
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1.0
U.S. and Foreign
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	28.4
U.S. and Foreign | Expiring between 2017 and 2019
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	5.0
U.S. and Foreign | Between 2020 and 2033
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	21.0
U.S. and Foreign | Indefinite
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	2.4
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	91.2
Foreign Tax Authority | Expiring between 2017 and 2019
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	0.9
Foreign Tax Authority | Tax Year 2026
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	42.9
Foreign Tax Authority | Indefinite
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 47.4