Balance Sheet Details (Tables)

12 Months Ended

Dec. 27, 2015

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 28, 2014		December 27, 2015
Billed	$	19.1	$	13.5
Unbilled	21.2		31.0
Total U.S. Government contract receivables	$	40.3	$	44.5

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

	December 28, 2014			December 27, 2015
Billed, current	$	119.0		$	96.6
Unbilled, current	100.4			112.0
Total current accounts receivable	219.4			208.6
Allowance for doubtful accounts	(1.9		)	(1.8		)
Total accounts receivable, net	$	217.5		$	206.8

Schedule of Inventory, Current

Inventoried costs, net of progress payments (in millions)

	December 28, 2014			December 27, 2015
Raw materials	$	30.1		$	32.9
Work in process	13.3			19.2
Finished goods	2.8			2.6
Supplies and other	2.1			1.6
Subtotal inventoried costs	48.3			56.3
Less customer advances and progress payments	(0.9		)	(0.7		)
Total inventoried costs	$	47.4		$	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 28, 2014			December 27, 2015
Land and buildings	$	12.8		$	13.3
Computer equipment and software	24.3			27.0
Machinery and equipment	41.0			47.4
Furniture and office equipment	10.0			5.8
Leasehold improvements	13.0			10.9
Construction in progress	8.0			5.7
Property and equipment	109.1			110.1
Accumulated depreciation and amortization	(47.5		)	(53.9		)
Total property and equipment, net	$	61.6		$	56.2