Certain Balance Sheet Components Summary of the Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of Allowance for Doubtful Accounts Activity [Line Items]
Allowance for Doubtful Accounts Receivable	$ 3,957	$ 3,320	$ 5,949	$ 6,195
Provision for Doubtful Accounts	1,656	60	1,025
Allowance for Doubtful Accounts Receivable, Write-offs	1,351	2,422	549
Effects of change in exchange rates	$ 332	$ (267)	$ (722)