Summarize Impact of ASC 606 to Condensed consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Apr. 01, 2018	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Accounts receivable, less allowance for doubtful accounts	$ 413,978		$ 272,783
Inventories, net	131,857		107,525
Deferred tax assets	77,705		84,026
LIABILITIES
Deferred revenue and customer advances	85,892		83,614
Income taxes payable	34,828		59,055
Long-term deferred revenue and customer advances	21,726		30,127
SHAREHOLDERS' EQUITY
Retained earnings	216,120		$ 272,013
ASU 2014-09
ASSETS
Accounts receivable, less allowance for doubtful accounts	346,250
Inventories, net	159,606
Deferred tax assets	80,628
LIABILITIES
Deferred revenue and customer advances	90,882	$ 76,638
Income taxes payable	29,661
Long-term deferred revenue and customer advances	30,904	20,848
SHAREHOLDERS' EQUITY
Retained earnings	170,063
ASU 2014-09 | Adjustments to Recognize under Legacy GAAP
ASSETS
Accounts receivable, less allowance for doubtful accounts	(67,728)
Inventories, net	27,749
Deferred tax assets	2,923
LIABILITIES
Deferred revenue and customer advances	4,990	9,254
Income taxes payable	(5,167)
Long-term deferred revenue and customer advances	9,178	$ 878
SHAREHOLDERS' EQUITY
Retained earnings	$ (46,057)