Acquisition - Narrative (Details) $ in Millions			3 Months Ended		6 Months Ended
	Feb. 28, 2019 USD ($)	Feb. 27, 2019 USD ($) shares	Jun. 30, 2019 USD ($)	Jul. 01, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jul. 01, 2018 USD ($)
Business Acquisition [Line Items]
Aggregate purchase price	$ 60.0
Shares issued		$ 27.0
Merger and acquisition expenses			$ 0.6	$ 0.0	$ 1.8	$ 0.0
FTT Inc
Business Acquisition [Line Items]
Percentage of voting interests acquired	80.10%	80.10%
FTT Core
Business Acquisition [Line Items]
Percentage of voting interests acquired	80.10%	80.10%
FTT
Business Acquisition [Line Items]
Percentage of voting interests acquired		80.10%
Aggregate purchase price		$ 60.0
Total cash paid		33.0
Cash paid	$ 17.7	20.7
Amount to be paid		$ 15.3
Payment period		3 years
Increase in minority interest purchase price over next 12 months		14
Current liabilities		$ 7.7
Long-term liabilities		1.3
Deferred tax liabilities		$ 4.4
Revenue			17.2		21.4
Operating income			1.6		1.7
Merger and acquisition expenses			$ 0.1		1.3
Amortization of intangible assets					$ 0.5
FTT | Common Stock
Business Acquisition [Line Items]
Number of shares issued (in shares) | shares		1,825,406
FTT | Customer relationships
Business Acquisition [Line Items]
Intangible assets acquired		$ 11.2
Useful life		10 years
FTT | In-process research and development
Business Acquisition [Line Items]
Intangible assets acquired		$ 6.0
FTT | Contracts and backlog
Business Acquisition [Line Items]
Intangible assets acquired		$ 2.2
Useful life		2 years
FTT | Trade names
Business Acquisition [Line Items]
Intangible assets acquired		$ 0.4
Useful life		1 year