Stock-Based Compensation - Restricted Stock (Details) - Restricted stock and restricted stock units	6 Months Ended
	Jul. 31, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Balance as of January 31, 2017 (in shares) | shares	330,000
Granted - restricted stock and restricted stock units (in shares) | shares	2,568,071
Vested and converted to shares (in shares) | shares	(100,000)
Canceled (in shares) | shares	(2,890)
Balance as of July 31, 2017 (in shares) | shares	2,795,181
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Balance as of January 31, 2017 (in dollars per share) | $ / shares	$ 6.54
Granted - restricted stock and restricted stock units (in dollars per share) | $ / shares	12.32
Vested and converted to shares (in dollars per share) | $ / shares	6.54
Canceled (in dollars per share) | $ / shares	12.31
Balance as of July 31, 2017 (in dollars per share) | $ / shares	$ 11.84