Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	3 Months Ended
	Apr. 30, 2017 vote	Feb. 01, 2017 USD ($)
Retained Earnings | Accounting Standards Update 2016-09 - Forfeiture Rate Component
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative impact adjustment | $		$ (0.2)
Class A Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of votes per share	1
Class B Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of votes per share	10