Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Dec. 01, 2018	Nov. 30, 2019	Dec. 01, 2018
Income Statement [Abstract]
Net sales	$ 674.2	$ 652.6	$ 1,345.2	$ 1,277.3
Cost of sales	418.7	417.0	843.6	816.6
Gross margin	255.5	235.6	501.6	460.7
Operating expenses:
Selling, general and administrative	169.5	163.2	334.3	322.7
Restructuring expense	4.2	0.3	6.1	1.4
Design and research	19.4	19.0	38.6	37.5
Total operating expenses	193.1	182.5	379.0	361.6
Operating earnings	62.4	53.1	122.6	99.1
Gain on consolidation of equity method investment	30.5	0.0	30.5	0.0
Other expenses (income):
Interest expense	3.0	3.1	6.0	6.0
Other (income) expense, net	(0.4)	0.7	(1.3)	(0.3)
Earnings before income taxes and equity income	90.3	49.3	148.4	93.4
Income tax expense	12.9	11.2	25.2	20.0
Equity income from nonconsolidated affiliates, net of tax	1.2	1.2	3.4	1.8
Net earnings	78.6	39.3	126.6	75.2
Net (loss) earnings attributable to noncontrolling interests	0.0	0.0	(0.2)	0.1
Net earnings attributable to Herman Miller, Inc.	$ 78.6	$ 39.3	$ 126.8	$ 75.1
Earnings per share — basic	$ 1.33	$ 0.66	$ 2.15	$ 1.27
Earnings per share — diluted	$ 1.32	$ 0.66	$ 2.14	$ 1.26
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	$ 13.7	$ (4.5)	$ 4.4	$ (12.4)
Pension and other post-retirement plans	0.7	0.4	1.4	1.1
Interest rate swaps	3.4	1.0	(5.3)	0.5
Unrealized holding loss	0.0	0.0	0.0	(0.1)
Other comprehensive loss, net of tax	17.8	(3.1)	0.5	(10.9)
Comprehensive income	96.4	36.2	127.1	64.3
Comprehensive (loss) income attributable to noncontrolling interests	0.0	0.0	(0.2)	0.1
Comprehensive income attributable to Herman Miller, Inc.	$ 96.4	$ 36.2	$ 127.3	$ 64.2