Balance Sheet Details (Tables)

12 Months Ended

Dec. 30, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Accounts, Notes, Loans and Financing Receivable

Receivables including amounts due under long-term contracts are summarized as follows (in millions):

	December 30, 2018			December 31, 2017
Billed, current	$	66.5		$	74.3
Unbilled, current	173.2			138.5
Total current accounts receivable	239.7			212.8
Allowance for doubtful accounts	(2.3		)	(0.5		)
Total accounts receivable, net	$	237.4		$	212.3

U.S. Government contract receivables where the Company is the prime contractor included in accounts receivable, net (in millions):

	December 30, 2018		December 31, 2017
Billed	$	16.5	$	16.9
Unbilled	83.1		55.1
Total U.S. Government contract receivables	$	99.6	$	72.0

Schedule of Inventory, Current

Inventoried costs, net of progress payments (in millions):

	December 30, 2018		December 31, 2017
Raw materials	$	34.7	$	35.9
Work in process	10.3		11.4
Finished goods	1.8		2.3
Subtotal inventoried costs	46.8		49.6
Less customer advances and progress payments	—		(0.6		)
Total inventoried costs	$	46.8	$	49.0

Property, Plant and Equipment

Assets are depreciated predominately using the straight-line method, with the following lives:

	Years
Buildings and improvements	15 – 39
Machinery and equipment	3 – 10
Computer equipment and software	1 – 10
Vehicles, furniture, and office equipment	5
Leasehold improvements	Shorter of useful life or length of lease

Property, plant and equipment, net (in millions)

	December 30, 2018			December 31, 2017
Land and buildings	$	11.9		$	12.1
Computer equipment and software	28.3			27.3
Machinery and equipment	56.8			49.7
Furniture and office equipment	6.3			5.1
Leasehold improvements	10.9			10.1
Construction in progress	21.5			17.3
Property and equipment	135.7			121.6
Accumulated depreciation and amortization	(68.6		)	(63.6		)
Total property and equipment, net	$	67.1		$	58.0