Summary of Significant Accounting Policies (Detail 4)	12 Months Ended
	Dec. 31, 2017
Buildings [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	39 Years
Machinery, equipment and tooling [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	3 Years
Machinery, equipment and tooling [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	10 Years
Leasehold improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	Lesser of life of lease or economic life
Furniture and fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	7 Years
Information systems [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	3 Years