Services Revenues from Professional Services and Customer Support and Software Enhancements (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting [Abstract]
Professional services									$ 333,438	$ 304,624	$ 260,058
Customer support and software enhancements									133,848	123,454	115,965
Total services revenue	$ 111,923	$ 119,267	$ 119,833	$ 116,263	$ 106,982	$ 112,549	$ 107,344	$ 101,203	$ 467,286	$ 428,078	$ 376,023