Significant Accounting Policies - Estimated Useful Life for Each Asset (Detail)	12 Months Ended
	Dec. 27, 2014
Minimum [Member] | Laboratory and manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	1 year 6 months
Minimum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	3 years
Minimum [Member] | Computer hardware and software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	1 year 6 months
Minimum [Member] | Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	1 year
Maximum [Member] | Laboratory and manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	10 years
Maximum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	5 years
Maximum [Member] | Computer hardware and software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	7 years
Maximum [Member] | Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	10 years