Balance Sheet Components - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Components [Abstract]
Inventory deposit	$ 34,141	$ 60,315
Prepaid income taxes	38,134	17,383
Other current assets	96,215	79,140
Other prepaid expenses and deposits	8,840	11,846
Total prepaid expenses and other current assets	$ 177,330	$ 168,684