Description of Business and Summary of Significant Accounting Policies - Summary of Prepaid Expense and Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expense and Other Assets [Abstract]
Prepaid expenses	$ 14,526	$ 14,001
Inventories	8,052	8,065
Supplemental deferred compensation plan assets	25,055	22,204
Other	24,483	11,141
Total prepaid expenses and other assets	$ 72,116	$ 55,411