Information about Contract Liabilities (Detail) - USD ($) $ in Thousands	Jul. 01, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue and customer advances	$ 82,491		$ 83,614
Long-term deferred revenue and customer advances	25,375		$ 30,127
ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue and customer advances	75,237	$ 76,638
Long-term deferred revenue and customer advances	15,539	20,848
ASU 2014-09 | Adjustments to Recognize Under Legacy GAAP
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue and customer advances	(7,254)	5,853
Long-term deferred revenue and customer advances	$ (9,836)	$ 4,527