Accumulated Other Comprehensive Income (Loss) - Changes in Each Component of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance			$ 526.8				$ 526.8
Total other comprehensive loss, net of tax	$ (33.8)	$ (13.2)	9.6	$ (15.8)	$ (49.8)	$ 31.0	(37.4)	$ (34.6)
Balance	529.2						529.2
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(138.5)		(134.9)	(104.2)		(85.4)	(134.9)	(85.4)
Other comprehensive income (loss) before reclassifications	(33.4)			(16.2)			(35.5)	(35.1)
Amounts reclassified from accumulated other comprehensive loss	(0.4)			0.4			(1.9)	0.5
Total other comprehensive loss, net of tax	(33.8)	(13.2)	9.6	(15.8)	(49.8)	31.0	(37.4)	(34.6)
Balance	(172.3)	(138.5)		(120.0)	(104.2)		(172.3)	(120.0)
Foreign Currency Translation [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(127.6)		(132.5)	(103.3)		(78.3)	(132.5)	(78.3)
Other comprehensive income (loss) before reclassifications	(35.6)			(17.7)			(30.7)	(42.7)
Amounts reclassified from accumulated other comprehensive loss	0.0			0.0			0.0	0.0
Total other comprehensive loss, net of tax	(35.6)			(17.7)			(30.7)	(42.7)
Balance	(163.2)	(127.6)		(121.0)	(103.3)		(163.2)	(121.0)
Unrecognized Post- Retirement Plan Losses [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(5.0)		(5.2)	(6.7)		(7.2)	(5.2)	(7.2)
Other comprehensive income (loss) before reclassifications	0.1			0.1			0.2	0.3
Amounts reclassified from accumulated other comprehensive loss	0.1			0.0			0.2	0.3
Total other comprehensive loss, net of tax	0.2			0.1			0.4	0.6
Balance	(4.8)	(5.0)		(6.6)	(6.7)		(4.8)	(6.6)
Derivative Financial Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(5.9)		$ 2.8	5.8		$ 0.1	2.8	0.1
Other comprehensive income (loss) before reclassifications	2.1			1.4			(5.0)	7.3
Amounts reclassified from accumulated other comprehensive loss	(0.5)			0.4			(2.1)	0.2
Total other comprehensive loss, net of tax	1.6			1.8			(7.1)	7.5
Balance	$ (4.3)	$ (5.9)		$ 7.6	$ 5.8		$ (4.3)	$ 7.6

Milacron Holdings Corp. 10-Q