Balance Sheet Components - Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses	$ 64,832	$ 79,258
Taxes receivable	110,961	102,002
Restrictive cash, current	26,919	15,065
Other receivables	7,797	46,809
Derivative instruments	4,175	54,072
Other current assets	17,343	22,190
Other current assets, total	$ 232,027	$ 319,396