CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jan. 31, 2017
Jan. 31, 2016
Jan. 31, 2017
Jan. 31, 2016
Statement of Comprehensive Income [Abstract]        
Net loss $ (93,212) $ (33,205) $ (255,381) $ (71,750)
Other comprehensive loss—net of tax:        
Change in unrealized loss on available-for-sale securities, net of tax (150) (26) (158) (1)
Total other comprehensive loss—net of tax (150) (26) (158) (1)
Comprehensive loss $ (93,362) $ (33,231) $ (255,539) $ (71,751)