Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	[3]
Statement of Comprehensive Income [Abstract]
Net loss	$ (64,304)	$ (57,159)	[1],[2]
Other comprehensive income (loss):
Change in unrealized net gain (loss) on available-for-sale securities	(716)	117
Comprehensive loss	$ (65,020)	$ (57,042)

[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018

[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.

[3] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.