Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	May 02, 2020	Apr. 27, 2019
Deferred taxes assets:
Accrued warranty obligations	$ 6,202	$ 5,912
Vacation accrual	1,753	1,571
Deferred maintenance revenue	987	716
Allowance for excess and obsolete inventory	1,318	1,340
Legal reserve	503	260
Equity compensation	396	486
Allowance for doubtful accounts	546	402
Inventory capitalization	822	567
Accrued compensation and benefits	539	549
Net operating loss carry forwards	919	1,059
Research and development tax credit carry forwards	1,975	1,299
Lease accounting - lease liability	2,099	0
Other	1,035	1,647
Deferred tax assets, gross	19,094	15,808
Valuation allowance	(1,189)	(893)
Deferred tax assets net of valuation	17,905	14,915
Deferred tax liabilities:
Property and equipment	(2,141)	(3,100)
Lease accounting - right of use asset	(2,103)	0
Prepaid expenses	(440)	(476)
Intangible assets	(317)	(623)
Unrealized gain on foreign currency exchange	17	6
Other	(68)	(75)
Deferred tax liabilities, gross	(5,086)	(4,280)
Deferred tax assets, net	$ 12,819	$ 10,635