Revenue - Impact of Adoption of ASU on Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Sep. 30, 2017
ASSETS
Receivables, less allowances for doubtful accounts	$ 221.5		$ 165.2
Inventories	13.8		23.3
Deferred income taxes	14.0		22.2
Total assets	913.4		893.5	$ 933.7
LIABILITIES
Accrued liabilities	137.3		119.2
EQUITY
Retained earnings	84.4		8.9
Total liabilities and equity	913.4		$ 893.5
ASU 2014-09
ASSETS
Receivables, less allowances for doubtful accounts		$ 174.1
Inventories		12.7
Deferred income taxes		21.7
Total assets		891.3
LIABILITIES
Accrued liabilities		116.1
EQUITY
Retained earnings		9.8
Total liabilities and equity		891.3
Previous Revenue Standard
ASSETS
Receivables, less allowances for doubtful accounts	215.7
Inventories	23.8
Deferred income taxes	14.5
Total assets	918.1
LIABILITIES
Accrued liabilities	142.7
EQUITY
Retained earnings	83.7
Total liabilities and equity	918.1
Adoption of ASU 2014-09 | ASU 2014-09
ASSETS
Receivables, less allowances for doubtful accounts	5.8	8.9
Inventories	(10.0)	(10.6)
Deferred income taxes	(0.5)	(0.5)
Total assets	(4.7)	(2.2)
LIABILITIES
Accrued liabilities	(5.4)	(3.1)
EQUITY
Retained earnings	0.7	0.9
Total liabilities and equity	$ (4.7)	$ (2.2)