Other Long-Term Obligations (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Liabilities, Noncurrent [Abstract]
Long-term lease obligations, net of current portion	$ 23,426	$ 23,152
Deferred proceeds	5,966	9,013
Deferred compensation	5,168	7,219
Other	6,382	2,392
Other long-term obligations	$ 40,942	$ 41,776