Commitments and Contingencies (Details) - Charitable Gift [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017	Jan. 31, 2018
Loss Contingencies [Line Items]
Long-term Purchase Commitment, Amount			$ 5,000
Loss Contingency Accrual	$ 4,546		4,546		$ 0
Selling, General and Administrative Expenses [Member]
Loss Contingencies [Line Items]
Loss Contingency, Loss in Period	0	$ 0	4,503	$ 0
Other Nonoperating Income (Expense) [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, Period Increase (Decrease)	43	$ 0	43	$ 0
Accrued Liabilities [Member]
Loss Contingencies [Line Items]
Loss Contingency, Accrual, Current	1,407		1,407		0
Other Noncurrent Liabilities [Member]
Loss Contingencies [Line Items]
Loss Contingency, Accrual, Noncurrent	$ 3,139		$ 3,139		$ 0