Segment Information (Detail) - Summarized Information by Geographic Location - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Revenues	$ 2,444,540	$ 2,163,056	$ 2,021,441
Long-lived assets:
Long-lived assets	210,877	211,113	190,338
United States and Canada
Revenues:
Revenues	1,519,748	1,347,676	1,204,476
Long-lived assets:
Long-lived assets	143,921	163,933	142,963
Europe, Middle East and Africa
Revenues:
Revenues	616,721	557,165	570,334
Long-lived assets:
Long-lived assets	42,326	31,130	34,093
Other International
Revenues:
Revenues	308,071	258,215	246,631
Long-lived assets:
Long-lived assets	$ 24,630	$ 16,050	$ 13,282