Stockholders' Equity - Narrative (Details)	Apr. 04, 2018 USD ($) $ / shares shares	Oct. 31, 2019 stock_class $ / shares shares	Aug. 31, 2019 USD ($)	Jan. 31, 2019 $ / shares shares
Class of Stock [Line Items]
Shares authorized (in shares)		20,000,000		20,000,000
Shares issued (in shares)		0		0
Shares outstanding (in shares)		0		0
Number of classes of stock | stock_class		2
Shares authorized (in shares)		2,250,000,000		2,250,000,000
Closing price of stock (in dollars per share) | $ / shares		$ 19.46
Class A
Class of Stock [Line Items]
Shares authorized (in shares)		2,000,000,000		2,000,000,000
Par value per share (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001
Shares issued (in shares)		259,920,406		243,524,000
Shares outstanding (in shares)		259,920,406		243,524,000
Value approved For repurchase | $			$ 150,000,000.0
Stock repurchased and retired (in shares)	1,008,573
Stock repurchased and retired during period, value | $	$ 20,000,000.0
Closing price of stock (in dollars per share) | $ / shares	$ 19.83	$ 19.46
Class B
Class of Stock [Line Items]
Shares authorized (in shares)		250,000,000		250,000,000
Par value per share (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001