Segment Reporting and Information about Geographic Areas - Schedule of Long-Lived Assets by Geographic Area (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 16,375,012	$ 11,902,839
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	15,587,979	11,399,545
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 787,033	$ 503,294