Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	35.00%
Current
Federal	$ (2.1)	$ 1.1	$ (16.7)
State	0.1	2.1	0.9
Current Income Tax Expense (Benefit)	(2.0)	3.2	(15.8)
Deferred
Federal	(0.6)	3.6	(36.8)
State	0.3	3.5	(3.8)
Deferred tax expense	(0.3)	7.1	(40.6)
Income tax provision	$ (2.3)	$ 10.3	$ (56.4)