Customer Accounts Receivable Delinquency Bucket (Details) - USD ($)	Apr. 30, 2020	Jan. 31, 2020
Financing Receivable, Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 245,146,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	737,137,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	352,790,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	97,309,000
Financing Receivable, Originated Four or More Years before Latest Fiscal Year	10,120,000
Carrying value of customer accounts receivable	1,442,502,000	$ 1,547,645,000
Percent of Total Accounts Receivable	1.000
Current [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	209,196,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	520,586,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	220,700,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	48,025,000
Financing Receivable, Originated Four or More Years before Latest Fiscal Year	3,041,000
Carrying value of customer accounts receivable	1,001,548,000
Percent of Total Accounts Receivable	0.695
Financial Asset, 1 to 29 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	24,977,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	100,147,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	56,044,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	17,624,000
Financing Receivable, Originated Four or More Years before Latest Fiscal Year	1,792,000
Carrying value of customer accounts receivable	200,584,000
Percent of Total Accounts Receivable	0.139
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	7,036,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	21,169,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	13,854,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	5,123,000
Financing Receivable, Originated Four or More Years before Latest Fiscal Year	687,000
Carrying value of customer accounts receivable	47,869,000
Percent of Total Accounts Receivable	0.033
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	3,937,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	18,003,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	9,810,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	4,060,000
Financing Receivable, Originated Four or More Years before Latest Fiscal Year	652,000
Carrying value of customer accounts receivable	36,462,000
Percent of Total Accounts Receivable	0.025
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	77,232,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	52,382,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	22,477,000
Financing Receivable, Originated Four or More Years before Latest Fiscal Year	3,948,000
Carrying value of customer accounts receivable	156,039,000
Percent of Total Accounts Receivable	$ 0.108