Summary of Significant Accounting Policies - Operating Income from Continuing Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	$ 159.4	$ 157.1	$ 453.6	$ 437.0
Total costs	115.3	119.9	329.4	326.2
Gross profit	44.1	37.2	124.2	110.8
Selling, general and administrative expenses	29.5	32.9	89.4	94.8
Operating income from continuing operations	10.1	0.1	19.7	3.0
Service
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	54.9	47.6	147.9	150.6
Total costs	34.3	32.7	100.4	106.8
Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	104.5	109.5	305.7	286.4
Total costs	81.0	$ 87.2	229.0	$ 219.4
Balances Without Adoption of ASC 606 | ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	154.1		432.6
Total costs	111.5		313.9
Gross profit	42.6		118.7
Selling, general and administrative expenses	29.5		89.4
Operating income from continuing operations	8.6		14.2
Balances Without Adoption of ASC 606 | ASC 606 | Service
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	54.9		147.9
Total costs	34.3		100.4
Balances Without Adoption of ASC 606 | ASC 606 | Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	99.2		284.7
Total costs	77.2		213.5
Effect of Change Higher/(Lower)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	5.3		21.0
Effect of Change Higher/(Lower) | ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	5.3		21.0
Total costs	3.8		15.5
Gross profit	1.5		5.5
Selling, general and administrative expenses	0.0		0.0
Operating income from continuing operations	1.5		5.5
Effect of Change Higher/(Lower) | ASC 606 | Service
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	0.0		0.0
Total costs	0.0		0.0
Effect of Change Higher/(Lower) | ASC 606 | Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	5.3		21.0
Total costs	$ 3.8		$ 15.5