Other Receivables and Current Assets and Other Long-Term Liabilities - Schedule of Other Receivables and Current Assets and Other Long-Term Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Other Receivables and Current Assets and Other Long-Term Liabilities [Abstract]
Receivables related to unrecognized revenue	$ 101,939	$ 167,144
Income taxes receivable, including overpayments and refunds	32,921	13,709
Prepaid expenses and other current assets	42,874	35,260
Total other receivables and current assets	177,734	216,113
Uncertain tax positions	33,105	29,279
Other long-term liabilities	29,379	32,294
Total other long-term liabilities	$ 62,484	$ 61,573