Revenue - Impact of Adoption of ASU on Condensed Consolidated Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Total net sales	$ 216.9	$ 222.6	$ 762.7	$ 780.1
Services cost of sales (exclusive of depreciation and amortization)	75.5	81.7	253.4	240.2
Products cost of sales (exclusive of depreciation and amortization)	57.8	58.9	204.1	190.7
Total cost of sales	133.3	140.6	457.5	482.7
Selling, general and administrative expenses (exclusive of depreciation and amortization)	62.6		203.8
Income tax expense (benefit)	19.7	2.1	31.5	22.0
Net earnings	$ 48.0	$ 5.3	$ 74.6	$ 33.4
Net earnings per share (Note 12):
Basic net earnings per share	$ 1.42	$ 0.16	$ 2.21	$ 1.01
Diluted net earnings per share	$ 1.40	$ 0.16	$ 2.19	$ 1.01
Previous Revenue Standard | ASU 2014-09
Total net sales	$ 219.4		$ 763.5
Services cost of sales (exclusive of depreciation and amortization)	75.5		253.0
Products cost of sales (exclusive of depreciation and amortization)	60.0		205.0
Total cost of sales	135.5		458.0
Selling, general and administrative expenses (exclusive of depreciation and amortization)	62.6		203.8
Income tax expense (benefit)	19.8		31.6
Net earnings	$ 48.2		$ 74.8
Net earnings per share (Note 12):
Basic net earnings per share	$ 1.43		$ 2.22
Diluted net earnings per share	$ 1.41		$ 2.20
Adoption of ASU 2014-09
Total net sales	$ (2.5)		$ (0.8)
Services cost of sales (exclusive of depreciation and amortization)			0.4
Products cost of sales (exclusive of depreciation and amortization)	(2.2)		(0.9)
Total cost of sales	(2.2)		(0.5)
Income tax expense (benefit)	(0.1)		(0.1)
Net earnings	$ (0.2)		$ (0.2)
Net earnings per share (Note 12):
Basic net earnings per share	$ (0.01)		$ (0.01)
Diluted net earnings per share	$ (0.01)		$ (0.01)
Services Net Sales
Total net sales	$ 138.5	$ 140.3	$ 485.9	$ 471.4
Services Net Sales | Previous Revenue Standard | ASU 2014-09
Total net sales	139.1		484.9
Services Net Sales | Adoption of ASU 2014-09
Total net sales	(0.6)		1.0
Products Net Sales
Total net sales	78.4	$ 82.3	276.8	$ 308.7
Products Net Sales | Previous Revenue Standard | ASU 2014-09
Total net sales	80.3		278.6
Products Net Sales | Adoption of ASU 2014-09
Total net sales	$ (1.9)		$ (1.8)