Balance Sheet Details (Tables)

12 Months Ended

Dec. 25, 2016

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Accounts, Notes, Loans and Financing Receivable

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

	December 25, 2016		December 27, 2015
Billed	$	15.6	$	13.5
Unbilled	39.3		31.0
Total U.S. Government contract receivables	$	54.9	$	44.5

Receivables including amounts due under long-term contracts are summarized as follows:

	December 25, 2016			December 27, 2015
Billed, current	$	102.8		$	96.6
Unbilled, current	128.3			112.0
Total current accounts receivable	231.1			208.6
Allowance for doubtful accounts	(1.7		)	(1.8		)
Total accounts receivable, net	$	229.4		$	206.8

Schedule of Inventory, Current

Inventoried costs, net of progress payments (in millions)

	December 25, 2016			December 27, 2015
Raw materials	$	31.9		$	32.9
Work in process	22.1			19.2
Finished goods	1.4			2.6
Supplies and other	1.8			1.6
Subtotal inventoried costs	57.2			56.3
Less customer advances and progress payments	(1.8		)	(0.7		)
Total inventoried costs	$	55.4		$	55.6

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 and equipment, net (in millions)

	December 25, 2016			December 27, 2015
Land and buildings	$	12.2		$	13.3
Computer equipment and software	26.9			27.0
Machinery and equipment	47.2			47.4
Furniture and office equipment	5.3			5.8
Leasehold improvements	9.9			10.9
Construction in progress	6.1			5.7
Property and equipment	107.6			110.1
Accumulated depreciation and amortization	(57.8		)	(53.9		)
Total property and equipment, net	$	49.8		$	56.2