Stock-Based Compensation - Nonvested Stock Options (Details) - $ / shares	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Options, nonvested, number of shares, beginning of the period	5,023,782
Options granted (in shares)	0
Options vested (in shares)	(2,604,077)
Options forfeited (in shares)	(298,267)
Options, nonvested, number of shares, end of the period	2,121,438
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested, options, weighted-average grant date fair value (in dollars per share), beginning of period	$ 4.35
Options granted, weighted-average grant date fair value (in dollars per share)	0	$ 5.79
Options vested, weighted-average grant date fair value (in dollars per share)	3.99
Options forfeited, weighted-average grant date fair value (in dollars per share)	4.03
Nonvested, options, weighted-average grant date fair value (in dollars per share), end of period	$ 4.83