Balance Sheet Account Details Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Prepaid Expense and Other Assets, Current [Abstract]
Other receivables	$ 7,215	$ 15,507
Prepaid expenses	5,278	4,508
Income taxes receivable	1,887	2,703
Other	2,732	928
Total prepaid expenses and other current assets	$ 17,112	$ 23,646