Revenue (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 01, 2018	Apr. 01, 2018	Mar. 26, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Rental income, not subject to ASC 606		$ 5.0	$ 6.0
Contract asset		3.2
Commutative catch up adjustment	$ 3.5
Consideration reclassified to accounts receivable		0.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-02
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation		14.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-02
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation		10.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-02
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation		9.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation		$ 33.0