Summary of Significant Accounting Policies Effect of adopting new accounting guidance (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Feb. 01, 2019	Jan. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance Lease, Right-of-Use Asset		$ 233
Right-of Use Assets, Operating Leases	$ 2,782	3,807	$ 0
Operating and Financing Lease, Liability, Current	2,065	1,446	0
Operating and Financing Lease Obligations, Noncurrent	$ 1,776	$ 2,571	$ 0