Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability, current	$ 13,752,000	$ 1,750,000
Transfers in or out Level 3, Assets	0	0
Transfers in or out Level 3, Liabilities	0	0
Transfers out of Level 1 to Level 2, Assets	0	0
Transfers into Level 1 out of Level 2, Assets	0	0
Transfers out of Level 1 to Level 2, Liabilities	0	0
Transfers into Level 1 out of Level 2, Liabilities	$ 0	0
Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Percentage of Probability Not Achieved of Contingent Consideration payment.	25.00%
Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Percentage of Probability Not Achieved of Contingent Consideration payment.	98.00%
Contingent Consideration [Member] | Revenue Based Milestones [Member] | NorMedix [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	23.50%
Contingent Consideration [Member] | Minimum [Member] | Non Revenue Based Milestones [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	2.70%
Contingent Consideration [Member] | Maximum [Member] | Non Revenue Based Milestones [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	3.00%
Level 3 Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability, current	$ 13,800,000	$ 1,800,000