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		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue Recognition, Milestone Method [Line Items]
License	$ 50,237	$ 57,653	$ 156,975	$ 154,732
Maintenance	59,262	63,764	178,895	188,572
Services	25,842	28,194	72,449	75,773
Total revenues	238,701	249,644	737,340	725,925
Vendor Specific Objective Evidence of Fair Value [Member]
Revenue Recognition, Milestone Method [Line Items]
License	1,885	5,466	5,810	18,106
Maintenance	923	1,862	2,738	6,275
Services	55	34	289	47
Total revenues	$ 2,863	$ 7,362	$ 8,837	$ 24,428