Fair Value Measurement - (Details) - USD ($) $ in Thousands	May 02, 2020	Apr. 27, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:	$ 1,230	$ 26,344
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:	1,230	3,464
U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		10,774
U.S. Government sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		10,482
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		1,624
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	40,398	35,383
Restricted cash	14	359
Derivatives - asset position	261
Derivatives - liability position	(17)	(4)
Assets (Liability), net	41,125	59,108
Recurring Basis | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:	1,230	3,464
Recurring Basis | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		10,774
Recurring Basis | U.S. Government sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		10,482
Recurring Basis | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		1,624
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	40,398	35,383
Restricted cash	14	359
Derivatives - asset position	0
Derivatives - liability position	0	0
Assets (Liability), net	40,412	46,516
Recurring Basis | Level 1 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:	0	0
Recurring Basis | Level 1 | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		10,774
Recurring Basis | Level 1 | U.S. Government sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		0
Recurring Basis | Level 1 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		0
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	0	0
Restricted cash	0	0
Derivatives - asset position	261	91
Derivatives - liability position	(17)	(4)
Assets (Liability), net	1,474	15,657
Recurring Basis | Level 2 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:	1,230	3,464
Recurring Basis | Level 2 | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		0
Recurring Basis | Level 2 | U.S. Government sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		10,482
Recurring Basis | Level 2 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		1,624
Reported Value Measurement [Member] | Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivatives - asset position		91
Acquisition-related contingent consideration	(761)	(3,065)
Estimate of Fair Value Measurement | Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivatives - asset position		0
Acquisition-related contingent consideration	0	0
Estimate of Fair Value Measurement | Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Acquisition-related contingent consideration	0	0
Estimate of Fair Value Measurement | Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	0	0
Restricted cash	0	0
Derivatives - asset position	0	0
Derivatives - liability position	0	0
Acquisition-related contingent consideration	(761)	(3,065)
Assets (Liability), net	(761)	(3,065)
Estimate of Fair Value Measurement | Recurring Basis | Level 3 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:	$ 0	0
Estimate of Fair Value Measurement | Recurring Basis | Level 3 | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		0
Estimate of Fair Value Measurement | Recurring Basis | Level 3 | U.S. Government sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		0
Estimate of Fair Value Measurement | Recurring Basis | Level 3 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale securities:		$ 0