Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Jan. 01, 2018
Summary Of Significant Accounting Policies [Line Items]
Revenue recognized in accordance with ASC 606	$ 566,848	$ 503,378	$ 1,581,244	$ 1,657,191
Revenue on leases	2,300		$ 10,200
Standard warranty period			12 months
Deferred revenue and customer advances balance	24,500		$ 70,900
ASU 2014-09
Summary Of Significant Accounting Policies [Line Items]
Revenue recognized in accordance with ASC 606	$ 564,500		$ 1,571,000
ASU 2017-07
Summary Of Significant Accounting Policies [Line Items]
Increase (decrease) in income from operations		$ 400		$ (1,300)
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)