Revenue from Contracts with Customers - Revenue Disaggregated By Product Type And Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Dec. 01, 2018	Nov. 30, 2019	Dec. 01, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 674.2	$ 652.6	$ 1,345.2	$ 1,277.3
North America Contract:
Disaggregation of Revenue [Line Items]
Net sales	450.6	434.8	909.3	855.8
North America Contract: | Systems
Disaggregation of Revenue [Line Items]
Net sales	145.3	145.3	292.6	291.4
North America Contract: | Seating
Disaggregation of Revenue [Line Items]
Net sales	129.7	126.9	259.9	252.5
North America Contract: | Freestanding and storage
Disaggregation of Revenue [Line Items]
Net sales	108.5	98.0	220.8	185.5
North America Contract: | Textiles
Disaggregation of Revenue [Line Items]
Net sales	29.8	29.5	76.3	58.3
North America Contract: | Other
Disaggregation of Revenue [Line Items]
Net sales	37.3	35.1	59.7	68.1
International Contract:
Disaggregation of Revenue [Line Items]
Net sales	118.2	118.5	232.0	234.0
International Contract: | Systems
Disaggregation of Revenue [Line Items]
Net sales	20.6	28.4	44.6	51.1
International Contract: | Seating
Disaggregation of Revenue [Line Items]
Net sales	67.0	62.1	128.3	130.8
International Contract: | Freestanding and storage
Disaggregation of Revenue [Line Items]
Net sales	13.8	13.9	28.5	24.3
International Contract: | Other
Disaggregation of Revenue [Line Items]
Net sales	16.8	14.1	30.6	27.8
Retail:
Disaggregation of Revenue [Line Items]
Net sales	105.4	99.3	203.9	187.5
Retail: | Seating
Disaggregation of Revenue [Line Items]
Net sales	68.4	58.1	129.1	111.8
Retail: | Freestanding and storage
Disaggregation of Revenue [Line Items]
Net sales	16.6	16.8	33.7	34.0
Retail: | Other
Disaggregation of Revenue [Line Items]
Net sales	$ 20.4	$ 24.4	$ 41.1	$ 41.7