Deferred Revenue and Advance Payments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deferred Revenue Disclosure [Abstract]
Deferred product licenses revenue, Current	$ 10,771	$ 13,023
Deferred subscription services revenue, Current	15,583	18,303
Deferred product support revenue, Current	141,496	162,781
Deferred other services revenue, Current	8,743	10,015
Gross current deferred revenue and advance payments	176,593	204,122
Less: unpaid deferred revenue, Current	(61,173)	(98,587)
Net current deferred revenue and advance payments	115,420	105,535
Deferred product licenses revenue, Non-current	7,320	9,118
Deferred subscription services revenue, Non-current	406	1,307
Deferred product support revenue, Non-current	5,790	5,751
Deferred other services revenue, Non-current	990	690
Gross non-current deferred revenue and advance payments	14,506	16,866
Less: unpaid deferred revenue, Non-current	(4,739)	(2,951)
Net non-current deferred revenue and advance payments	$ 9,767	$ 13,915