Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jul. 31, 2020	Feb. 01, 2020	Jan. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Customer accounts receivable	$ 514,528	$ 624,042	$ 673,742
Long-term customer accounts receivable, net	479,632	614,799	663,761
Deferred income taxes	43,243	40,771	18,599
Retained Earnings	$ 458,464	494,146	$ 570,636
98662000
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Customer accounts receivable		(49,700)
Long-term customer accounts receivable, net		(48,962)
Deferred income taxes		22,172
Retained Earnings		$ (76,490)