Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Line Items]
U.S. federal statutory tax rate	21.00%			24.50%	35.00%	35.00%
Discrete tax expense		$ 1,200,000	$ 1,600,000
Increase (Decrease) in deferred tax assets				$ 960,000	$ 665,000	$ (2,500,000)
Excess tax benefits (shortfalls) related to stock based compensation expense				2,000,000	(200,000)	600,000
Deferred tax asset valuation allowance				$ 4,541,000	4,511,000
Net operating loss carryforwards, remaining period				9 years
Unrecognized tax benefits excluding interest and penalties that would impact effective tax rate				$ 1,400,000	1,200,000	1,200,000
Liability for unrecognized tax benefits to change significantly in the next 12 months				400,000	500,000	600,000
Undistributed earnings in foreign subsidiaries				0	$ 0
Federal and State [Member] | 2033 [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards				$ 1,300,000
Net operating loss carryforwards, beginning of expiration year				2033
Federal and State [Member] | 2022 [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards				$ 300,000
Net operating loss carryforwards, beginning of expiration year				2022
Ireland and Luxembourg [Member] | Creagh Medical Ltd [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards				$ 3,200,000
R&D Credit Carryforwards [Member] | Federal and State [Member] | 2029 [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforwards				$ 1,900,000
Tax credit carryforward, beginning of expiration year				2029
In Vitro Diagnostics [Member]
Income Tax Disclosure [Line Items]
Capital losses generated						7,500,000
Increase (Decrease) in deferred tax assets						$ (2,600,000)