Condensed Consolidated Financial Statements - Revenues in Condensed Consolidated Statements of Operations from Arrangements for which Vendor-Specific Objective Evidence of Fair Value Does Not Exist for Each Undelivered Element (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue Recognition, Milestone Method [Line Items]
License	$ 37,423	$ 39,577
Maintenance	57,331	59,492
Services	19,576	23,497
Total revenues	226,066	232,817
Vendor Specific Objective Evidence of Fair Value [Member]
Revenue Recognition, Milestone Method [Line Items]
License	1,691	2,007
Maintenance	997	943
Services	78	103
Total revenues	$ 2,766	$ 3,053