Segment Information - Long-Lived Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Company's long-lived assets	$ 10,682,826	$ 9,394,602
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Company's long-lived assets	4,949,906	4,425,077
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Company's long-lived assets	3,602,758	3,265,088
Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Company's long-lived assets	$ 2,130,162	$ 1,704,437