Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 30, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)	Jan. 02, 2016 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of reportable segments | Segment	2
Percentage of completion revenue	$ 27,676,000	$ 23,300,000	$ 32,078,000
Advance payments on long-term contracts	2,945,000	5,158,000
Due from bankers acceptances drafts	15,960,000	7,852,000
Restricted cash	$ 1,421,000	2,082,000
Weighted average useful life of acquired intangible assets	12 years
Amortization expense of acquired intangible assets	$ 11,957,000	8,132,000	$ 5,007,000
Estimated Future Amortization Expense [Abstract]
2018	14,409,000
2019	13,482,000
2020	12,882,000
2021	12,340,000
2022	11,536,000
Thereafter	51,482,000
Goodwill and Intangible Asset Impairment [Abstract]
Goodwill impairment	0	0
Impairment of intangible assets	0	0
Recent Accounting Pronouncements [Abstract]
Reduction to retained earnings	(342,893,000)	$ (321,050,000)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Minimum | Pro Forma
Recent Accounting Pronouncements [Abstract]
Reduction to retained earnings	100,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Maximum | Pro Forma
Recent Accounting Pronouncements [Abstract]
Reduction to retained earnings	$ 300,000
Joint Venture with an Italian Company
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Ownership interest	50.00%
Remaining ownership interest with an option to purchase	50.00%