Services Revenues from Professional Services and Customer Support and Software Enhancements (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting [Abstract]
Professional services	$ 80,994	$ 69,398	$ 230,201	$ 194,522
Customer support and software enhancements	31,555	29,120	90,895	84,428
Total services revenue	$ 112,549	$ 98,518	$ 321,096	$ 278,950