Reportable Segments - Operating Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 233,371	$ 236,933	$ 288,498	$ 257,246	$ 239,476	$ 228,552	$ 224,538	$ 225,589	$ 1,016,048	$ 918,155	$ 871,922
Income from operations									(48,307)	(83,519)	(121,664)
Interest expense, net									41,355	9,505	5,289
Other income									0	(1,305)	(1,138)
Income before income taxes									6,952	75,319	117,513
Identifiable assets	2,071,754				1,070,366				2,071,754	1,070,366
Capital expenditures									33,796	95,438	37,698
Depreciation and amortization									63,402	42,359	34,830
Operating Segment
Segment Reporting Information [Line Items]
Income from operations									(93,827)	(146,119)	(161,020)
General corporate
Segment Reporting Information [Line Items]
Income from operations									(45,520)	(62,600)	(39,356)
Identifiable assets	308,384				62,054				308,384	62,054
Capital expenditures									0	6,677	11,208
Depreciation and amortization									2,667	1,961	733
Medical
Segment Reporting Information [Line Items]
Net sales									468,078	523,669	473,937
Medical | Operating Segment
Segment Reporting Information [Line Items]
Income from operations									(56,065)	(98,356)	(86,833)
Identifiable assets	549,194				532,250				549,194	532,250
Capital expenditures									15,587	52,907	18,996
Depreciation and amortization									24,133	23,033	19,002
Life Sciences
Segment Reporting Information [Line Items]
Net sales									195,410	194,950	211,210
Life Sciences | Operating Segment
Segment Reporting Information [Line Items]
Income from operations									(26,904)	(17,528)	(35,100)
Identifiable assets	157,115				184,737				157,115	184,737
Capital expenditures									2,134	16,408	4,409
Depreciation and amortization									6,856	7,482	5,628
Dental
Segment Reporting Information [Line Items]
Net sales									322,398	167,680	155,180
Dental | Operating Segment
Segment Reporting Information [Line Items]
Income from operations									(3,378)	(25,313)	(31,707)
Identifiable assets	1,037,947				272,309				1,037,947	272,309
Capital expenditures									15,304	16,243	2,441
Depreciation and amortization									29,702	9,844	8,756
Dialysis
Segment Reporting Information [Line Items]
Net sales									30,162	31,856	31,595
Dialysis | Operating Segment
Segment Reporting Information [Line Items]
Income from operations									(7,480)	(4,922)	(7,380)
Identifiable assets	$ 19,114				$ 19,016				19,114	19,016
Capital expenditures									771	3,203	644
Depreciation and amortization									$ 44	39	711
Restatement Adjustment | Life Sciences
Segment Reporting Information [Line Items]
Net sales										(6,072)	(5,820)
Income from operations										3,024	1,703
Restatement Adjustment | Dental
Segment Reporting Information [Line Items]
Net sales										6,072	5,820
Income from operations										$ (3,024)	$ (1,703)