Uncrecognized Tax Benefits and Tax Reform (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 6.4	$ 5.8	$ 5.6
Additions based on tax positions related to the current year	0.0	0.0	0.0
Additions for tax positions of prior years	0.6	0.8	0.8
Reductions for tax positions of prior years	0.0	0.0	(0.4)
Reductions for expirations of statute of limitations	(0.9)	(0.2)	(0.2)
Settlements	(1.8)	0.0	0.0
Balance at December 31	4.3	6.4	5.8
Unrecognized tax benefits, accumulated interest and penalties	6.6	6.8	6.1
Deferred tax assets related to unrecognized tax benefits	2.4	2.8	4.2
Net unrecognized tax benefits, associated interest, penalties and deferred tax asset that if resolved would impact effective tax rate	8.5	10.4	7.7
Recognized interest and penalties	$ 0.6	$ 0.4	$ 0.4
Income tax provision at statutory rate, %	21.00%	35.00%	35.00%
Adjustment to provisional estimate for enactment of new tax legislation, amount	$ 5.0	$ 41.3
Adjustment to provisional estimate for enactment of new tax legislation, impact to effective tax rate	0.90%