Segment Information - Balance Sheet Information by Operating Segments (Detail) - USD ($) $ in Thousands		12 Months Ended
		May 02, 2021		May 03, 2020		Apr. 28, 2019
Segment Reporting Information [Line Items]
inventory		$ 55,917		$ 47,907
property, plant, and equipment		44,003		43,147
right of use asset		11,730		3,903
investment in unconsolidated joint venture				1,602
total assets		214,080		215,084
cash and cash equivalents		37,009		69,790
short-term investments - available for sale		5,542		923
short-term investments - held to maturity		3,161		4,271
current income taxes receivable				1,585
deferred income taxes		545		793
other current assets		3,852		2,116
intangible assets		3,004		3,380
long-term investments - held-to-maturity		1,141		2,076
long-term investments - rabbi trust		8,415		7,834
other assets		2,035		664
capital expenditures	[1]	6,905		4,633		$ 2,975
depreciation		6,846		7,827		8,117
Operating Segments [Member]
Segment Reporting Information [Line Items]
total assets		147,055		118,912
depreciation		6,846		7,827		8,117
Operating Segments [Member] | Mattress Fabrics [Member]
Segment Reporting Information [Line Items]
accounts receivable		20,427		12,212
inventory		30,047		26,620
property, plant, and equipment		41,264	[2]	40,682	[3]
right of use asset		4,278	[4]	362	[5]
investment in unconsolidated joint venture				1,602
total assets		96,016		81,478
capital expenditures	[1]	6,226		3,475		2,526
depreciation		6,014		6,712		7,008
Operating Segments [Member] | Upholstery Fabrics [Member]
Segment Reporting Information [Line Items]
accounts receivable		17,299		12,881
inventory		25,870		21,287
property, plant, and equipment		1,925	[6]	1,633	[7]
right of use asset		5,945	[8]	1,633	[9]
total assets		51,039		37,434
capital expenditures	[1]	347		348		382
depreciation		832		765		787
Operating Segments [Member] | Discontinued Operation [Member]
Segment Reporting Information [Line Items]
capital expenditures	[1]			135		53
depreciation				350		322
Unallocated Corporate [Member]
Segment Reporting Information [Line Items]
property, plant, and equipment	[10]	814		832
right of use asset	[11]	1,507		1,908
total assets		214,080		215,084
cash and cash equivalents		37,009		69,790
short-term investments - available for sale		5,542		923
short-term investments - held to maturity		3,161		4,271
current income taxes receivable				1,585
deferred income taxes		545		793
other current assets		3,852		2,116
intangible assets		3,004		3,380
long-term investments - held-to-maturity		1,141		2,076
long-term investments - rabbi trust		8,415		7,834
other assets		2,035		664
capital expenditures	[1]	$ 332		$ 675		$ 14

[1] Capital expenditure amounts are stated on an accrual basis. See the Consolidated Statement of Cash Flows for capital expenditure    amounts on a cash basis.

[2] The $41.3 million as of May 2, 2021, represents property, plant, and equipment of $28.4 million, $12.0 million, and $855,000 located in the U.S., Canada, and Haiti, respectively.  

[3] The $40.7 million as of May 3, 2020, represents property, plant, and equipment of $27.7 million and $13.0 million located in the U.S. and Canada, respectively.  

[4] The $4.3 million as of May 2, 2021, represents right of use assets of $2.4 million, $1.4 million, and $400,000 located in Haiti, the U.S., and Canada, respectively.

[5] The $362,000 as of May 3, 2020, represents right of use assets located in the U.S.

[6] The $1.9 million as of May 2, 2021, represents property, plant, and equipment of $1.1 million and $850,000 located in the U.S. and China, respectively.  

[7] The $1.6 million as of May 3, 2020, represents property, plant, and equipment of $1.2 million and $471,000 located in the U.S. and China, respectively.

[8] The $5.9 million as of May 2, 2021, represents right of use assets of $5.0 million and $952,000 located in China and the U.S., respectively.

[9] The $1.6 million as of May 3, 2020, represents right of use assets of $857,000 and $776,000 located in the U.S. and China, respectively.

[10] The $814,000 as of May 2, 2021, and $832,000 as of May 3, 2020, represent property, plant, and equipment associated with unallocated corporate departments and corporate departments shared by both the mattress fabrics and upholstery fabrics segments located in the U.S.

[11] The $1.5 million as of May 2, 2021, and $1.9 million as of May 3, 2020, represents right of use assets located in the U.S. associated with unallocated corporate departments and corporate departments shared by both the mattress fabrics and upholstery fabrics segments located in the U.S.