Organization and Summary of Significant Accounting Policies - Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ 712.0				$ 724.5				$ 712.0	$ 724.5
Revenue	185.1	$ 184.1	$ 187.9	$ 160.4	164.4	$ 159.4	$ 151.2	$ 143.0	717.5	618.0	$ 603.3
Remaining performance obligation	601.2								601.2
Provision for loss on contracts	3.1				5.1				3.1	5.1
Contract assets, Net change									6.6
Contract liabilities, Net change									(2.7)
Revenue recognized									30.5	35.5
Contract assets	179.4								179.4			$ 172.8
Unbilled
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable	4.7				$ 3.8				4.7	$ 3.8
Unbilled | T for C
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract assets	11.5								11.5
Unbilled | International Customer
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract assets	$ 10.0								10.0
Effect of Change Higher/(Lower)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue									30.0
Cost of revenue									$ 21.9
ASC 606 Adjustment | ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit													$ 0.2