Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended
	Jan. 01, 2018	Apr. 01, 2018	Apr. 02, 2017
Summary Of Significant Accounting Policies [Line Items]
Revenue recognized in accordance with ASC 606		$ 487,467	$ 456,913
Revenue on leases		$ 4,300
Standard warranty period		12 months
Deferred revenue and customer advances balance	$ 21,800
ASU 2014-09
Summary Of Significant Accounting Policies [Line Items]
Revenue recognized in accordance with ASC 606		$ 483,200
ASU 2017-07
Summary Of Significant Accounting Policies [Line Items]
Increase in income from operations			$ 400
Retained Earnings | ASU 2014-09
Summary Of Significant Accounting Policies [Line Items]
Increase (decrease) in adoption of new accounting guidance amount	12,700
Retained Earnings | ASU 2016-01
Summary Of Significant Accounting Policies [Line Items]
Increase (decrease) in adoption of new accounting guidance amount	3,100
Accumulated Other Comprehensive Income (Loss) | ASU 2016-01
Summary Of Significant Accounting Policies [Line Items]
Increase (decrease) in adoption of new accounting guidance amount	$ (3,100)